Yellowstone

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  • Country
  • Volcanic Region
  • Primary Volcano Type
  • Last Known Eruption
  • 44.43°N
  • 110.67°W

  • 2805 m
    9200 ft

  • 325010
  • Latitude
  • Longitude

  • Summit
    Elevation

  • Volcano
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Most Recent Bulletin Report: February 2010 (BGVN 35:02) Citation IconCite this Report


Second largest recorded earthquake swarm during January-February 2010

Monthly updates from the Yellowstone Volcano Observatory (YVO) summarize seismic activity (table 1) and ground deformation at Yellowstone caldera. Earthquake activity remained at low levels during the majority of the reporting interval (November 2006 through February 2010). There were several earthquake swarms during this time, including significant events in December 2008-January 2009 and January-February 2010. The early 2010 events comprised the second largest earthquake swarm recorded at Yellowstone, second only to the fall 1985 swarm (BGVN 17:03). The swarm that began in December 2008 was the third largest swarm recorded.

Table 1. Seismic data for Yellowstone organized by month, including the number of recorded earthquakes, the largest magnitude recorded, and earthquake swarm information. Note the large swarms during December 2008-January 2009 and during January-February 2010. Data courtesy of the USGS.

[Skip text table]
    Month        Number of     Largest magnitude    Earthquake swarms
                earthquakes                         dates (number of events)

    Nov 2006         87          2.7 on 04 Nov      04-07 Nov (47)
    Dec 2006         36          2.0 on 16 Dec      --
    Jan 2007         93          2.8 on 30 Jan      --
    Feb 2007        113          2.9 on 27 Feb      27-28 Feb (5); 13-22 Feb (59)
    Mar 2007         63          2.3 on 21 Mar      11 on 1 Mar
    Apr 2007         53          2.1 on 22 Apr      --
    May 2007         59          2.7 on 01 May      01 May (14)
    Jun 2007         73          1.5 on 27 Jun      20 June (26)
    Jul 2007         80          2.2 on 26 Jul      --
    Aug 2007         74          2.8 on 03 Aug      19-21 Aug ("small" event)
    Sep 2007         54          2.3 on 10 Sep      --
    Oct 2007         34          2.1 on 17 Oct      --
    Nov 2007         69          2.9 on 04 Nov      --
    Dec 2007        184          3.6 on 30 Dec      18-21 Dec (48)
    Jan 2008        263          3.7 on 09 Jan      09 Jan (124); 25-26 Jan (32)
    Feb 2008        130          2.4 on 03 Feb      03 Feb (47)
    Mar 2008        147          4.2 on 25 Mar      11-16 Mar (73); 21-22 Mar (17)
    Apr 2008         70          1.7 on 17 Apr      --
    May 2008         99          2.3 on 18 May      04-14 May (37)
    Jun 2008         79          2.7 on 04 Jun      04-08 Jun (27)
    Jul 2008        185          2.5 on 31 Jul      28-31 Jul (132)
    Aug 2008        146          2.3 on 31 Aug      01-05 Aug (52); 03-07 Aug (28);
                                                      07-08 Aug (32)
    Sep 2008         62          2.9 on 25 Sep      25 Sep (19)
    Oct 2008         46          2.4 on 05 Oct      --
    Nov 2008        166          2.7 on 23 Nov      23-29 Nov (77)
    Dec 2008       ~500          3.9 on 27 Dec      27 Dec-05 Jan (~ 813)
    Jan 2009        315          3.5 on 02 Jan      09-12 Jan (35)
    Feb 2009         51          2.1 on 19 Feb      --
    Mar 2009         66          2.4 on 03 Mar      --
    Apr 2009        242          2.7 on 28 Apr      13-18 Apr (62); 17-25 Apr (111);
                                                      29 Apr (19)
    May 2009        133          3.0 on 25 May      25 May (68)
    Jun 2009         77          3.3 on 30 Jun      30 Jun (25)
    Jul 2009         98          2.7 on 08 Jul      01-03 Jul (12)
    Aug 2009         86          2.1 on 14 Aug      08-12 Aug (29)
    Sep 2009        177          2.3 on 20 Sep      12-17 Sep (39); 13-18 Sep (66)
    Oct 2009        218          2.5 on 15 Oct      12-23 Oct (138)
    Nov 2009         69          3.1 on 09 Nov      --
    Dec 2009         70          2.2 on 18 Dec      --
    Jan 2010       1620          3.8 on 20 Jan      17 Jan-25 Feb (1,809)
    Feb 2010        244          3.1 on 02 Feb      --

Earthquake swarm, December 2008-January 2009. An earthquake swarm from 26 December 2008 to 5 January 2009 was centered beneath the N end of Yellowstone Lake. The event consisted of ~ 900 earthquakes with magnitudes ranging up to 3.9; 19 events had magnitudes greater than 3.0, while 141 had magnitudes between 2.0 and 2.9.

Earthquake swarm, January-February 2010. The January-February 2010 earthquake swarm was centered about 16 km NW of Old Faithful, on the NW edge of the caldera. The event began with a few small earthquakes on 15 January and began to intensify on 17 January. A 3.7 magnitude earthquake was recorded at 2301 on 20 January, followed by a magnitude 3.8 event at 2316. The events were felt throughout the park and surrounding communities in Wyoming, Montana, and Idaho. By 25 February, YVO had recorded a total of 1,809 earthquakes, with 14 reaching magnitudes of over 3.0 and 136 with magnitudes between 2.0 and 2.9. By the end of February activity had returned to background levels.

The University of Utah Seismology Research Group stated that the total seismic energy released by all the earthquakes in this swarm corresponded to one earthquake with an approximate magnitude of 4.4. YVO emphasized that while this was an unusually large event, it did not indicate premonitory volcanic or hydrothermal activity. Rather, the swarm earthquakes were likely the result of slip on pre-existing faults.

Information Contacts: Yellowstone Volcano Observatory, U.S. Geological Survey, 345 Middlefield Road, Menlo Park, CA 94025, USA (URL: http://volcanoes.usgs.gov/yvo/).

The Global Volcanism Program has no Weekly Reports available for Yellowstone.

Bulletin Reports - Index


Reports are organized chronologically and indexed below by Month/Year (Publication Volume:Number), and include a one-line summary. Click on the index link or scroll down to read the reports.

09/1989 (SEAN 14:09) Shallow steam explosion destroys geyser

03/1992 (BGVN 17:03) Strong new thermal activity

10/1995 (BGVN 20:10) New mud volcano, minor mud flow, and associated thermal features

09/1999 (BGVN 24:09) Earthquake swarm during June along mapped faults

05/2000 (BGVN 25:05) On 2 May powerful Steamboat geyser discharged over 190 m3 of water

07/2003 (BGVN 28:07) Geyser basin heats up, affecting thermal features

02/2006 (BGVN 31:02) Low seismicity; ongoing ground-surface deformation

02/2010 (BGVN 35:02) Second largest recorded earthquake swarm during January-February 2010




Information is preliminary and subject to change. All times are local (unless otherwise noted)


September 1989 (SEAN 14:09) Citation IconCite this Report


Shallow steam explosion destroys geyser

The following is from Roderick Hutchinson. "At approximately 1440 on 5 September, Porkchop Geyser in the Norris Geyser Basin (roughly 44.7°N, 110.7°W) of Yellowstone National Park was destroyed by a shallow steam explosion. Eight visitors witnessed its water-steam mixture eruption column reach an estimated height of 20-30 m from its normal 6-9 m shortly before the whole siliceous sinter formation suddenly blew up. In 'just a few seconds' it threw sinter blocks out in a fan-like manner, mainly to the N and S, rupturing the geyser's vent, hot water basin, and surrounding sinter sheet platform. Maximum range of ejecta was 66.1 m S, 43.4 m N, 31.5 m W, and only 25.6 m E toward the boardwalk. An ejecta rim 1-1.4 m high, 13.9 m long on a N-S axis, and 11.7 m wide was formed around a newly created boiling spring. Much of its volume consisted of large sheets or plates of moderate to dense siliceous sinter buckled loose from the floor of the thermal basin and thrust vertically or overturned. The largest sinter block cast out had dimensions of 1.88 x 1.23 x 0.75 m. Within the ejecta rim, a new hot spring, supersaturated with silica, has emerged and is currently 5.5 x 4.0 m across and 3.23 m deep.

"Porkchop Geyser was a small unnamed spring, notable at least as early as 1927, because of its exceptionally high contents of Cl and SiO2; it remained unnamed until 1961, when it was informally called Dr. More's Porkchop by Donald E. White of the USGS, and later shortened to Porkchop Geyser. The name was derived from the shape of the geyser's pool. Porkchop normally had a slightly surging non-opalescent discharge; rarely, a geyser eruption 3-5 m high emptied its pool. Beginning in late Mar 1985, it started erupting as a perpetual spouter from an empty crater through its 2'3.5 cm triangular vent. Over the last 4 years, the geyser's eruption column was of sufficient velocity to be atomized into a fine spray that during winter formed ice cones > 7 m high and produced an eruption roar audible up to 2 km away.

"The destruction of Porkchop Geyser coincided with and was probably triggered by an annual widespread thermal disturbance in the Norris Geyser Basin. These hydrothermal events are characterized by briefly increased water and gas discharge, increased turbidity, extreme fluctuations in surface temperatures, alteration of geyser eruptive patterns, and in some years also include the creation of new thermal features. These disturbances have been observed nearly every year since 1971 when more detailed record keeping began."

Further References. Dzurisin, D., and Yamashita, K., 1987, Vertical surface displacements at Yellowstone Caldera, Wyoming, 1976-1986: JGR, v. 92, p. 13,753-13,766.

Smith, R.B., Reilinger, R., Meertens, C., Hollis, J., Holdahl, S., Dzurisin, D., Gross, W., and Klingele, E., 1989, What's moving at Yellowstone?; the 1987 crustal deformation survey from GPS, leveling, precision gravity, and trilateration: EOS, v. 70, p. 113, 119, 123-125.

Information Contacts: Roderick A. Hutchinson, Yellowstone National Park.


March 1992 (BGVN 17:03) Citation IconCite this Report


Strong new thermal activity

In 1985, a new superheated fumarole formed on the upper E margin of the Mushpots thermal area, which lies on the E side of the caldera associated with the youngest of Yellowstone's three cycles of voluminous rhyolitic volcanism, 0.6 million years ago. The presence of vegetation and the limited extent of bare thermal ground indicated that heat flow near the site of the new fumarole had been moderate to low for at least the previous 15 years. Interviews with park personnel strongly suggested that activity began about 3 July 1985. The steam cloud from the vent may have inspired a false report of smoke from the area, but the vent was not discovered until 5 October 1986, during fieldwork by C. Craig-Hunter and Roderick Hutchinson. At that time, the fumarole's transparent dry-steam jet was directed upslope N35°W at an approximate angle of 21°. A small, reddish-brown, iron-stained cone of hydrothermally altered sand-sized material had grown ~ 0.5 m above the uphill side of the rectangular 1.35 x 1.9-m vent, which dipped at an angle under the lower S rim. Just below the fumarole, on the floor of an old thermal zone, were numerous new or recently enlarged, small, steaming, thermal and mud pot vents, covering an area ~ 10 m in diameter. Sulfate and/or yellow elemental sulfur deposits covered most of the area and nearby slopes to the W, SW, and NW. A second area of new or rejuvenated thermal vents was also discovered in the drainage to the south.

Many trees had been killed in line with the fumarole's directed plume and around the margins of the old thermal zone. Mature trees as much as 87 cm in diameter were snapped off at ground level or uprooted, and tops were broken on other trees 40 m from the rim of the old thermal zone (54 m from the fumarole). A narrow zone of hydrothermally altered white chips of glacial till was found among the toppled trees up to 40 m from the thermal zone rim. These ejecta were 6 cm deep on the rim in 1986.

Geologists returned on 12 February 1987, after a nearby Univ of Utah seismograph . . . detected an isolated episode resembling volcanic tremor. The fumarole's temperature had increased (figure 1) and more elemental sulfur and iron sulfates had been deposited in the old thermal zone, but no other changes were evident. Since then, a biannual survey has been conducted in the area.

Figure (see Caption) Figure 1. Temperatures measured at Mushpot Fumarole, Yellowstone National Park, 5 October 1986-28 March 1992. Courtesy of R. Hutchinson.

During fieldwork on 28 March 1992, a quiet cloud of wet, 93°C vapor filled the 1985 fumarole's vent. However, less than 30 m downslope (S), on the E margin of the old thermal zone's floor, the ground was shaking violently with the formation and growth of a new mud pot. Bursts of thick, viscous mud were typically doming to 2 m and occasionally to 5 m in diameter before exploding to 3-6 m height. Each explosion shook the ground in all directions. Branches of thermally killed trees shook 50 m away, the ground was visibly moving 8-10 m from the rim, and within 4 m of the rim was behaving like pudding, with violent shaking causing surface oscillations of 1-2 cm. During 90 minutes of observations, the surface area of the mud pot increased by ~ 50%, to an estimated 11 x 7 m. It had a depth of at least 2 m. The minimal amount of ejected mud surrounding the crater and the intense shaking suggested that development of the mud pot had begun within the last 24 hours.

Information Contacts: Roderick A. Hutchinson, Yellowstone National Park.


October 1995 (BGVN 20:10) Citation IconCite this Report


New mud volcano, minor mud flow, and associated thermal features

On the SW flank of Sour Creek resurgent dome W of Astringent Creek in the 0.6 Ma Yellowstone caldera, is an extensive, unnamed acid sulfate hydrothermal system (figures 2 and 3). Surface expression of the ~3 km2 thermal area consists of discontinuous high temperature altered ground, turbid springs, pools, seeps, fumaroles, mud pots, a large gas- and sulfur-rich acid lake, and numerous sublimated sulfur mound deposits interspersed among low-temperature forest-covered ground.

Figure (see Caption) Figure 2. Index map of the western United States showing the location of Yellowstone Caldera.
Figure (see Caption) Figure 3. Sketch map of Yellowstone Caldera indicating the location of the recent thermal features described in this and an earlier report.

During early 1990, a significant rise in temperature in the upper NW end of the hydrothermal system began killing old-growth pine trees. Within a year, a new super-heated fumarole emerged, blanketing the downed trees and roots with a layer of hydrothermally altered coarse sand from a directed blast to the N.

The temperature and volume of dry steam venting from the deep "shaft-like" vent steadily increased over the next three years, with the temperature reaching a maximum of 104.3°C on 8 October 1994, ~11°C higher than the local boiling point. The dynamic activity of the fumarole and surrounding hot ground was only monitored about twice a year over the three years following its 1990 inception due to its remote location and restricted access.

A similar progression was previously seen during 1985 in an area ~4.5 km to the E. This area, the upper E margin of the Mushpots thermal area, sits on the W flanks of Pelican Cone (BGVN 17:03). The progression went from new hot ground and dying mature forests, to the vigorous breakout of a dry, super-heated fumarole with progressively hotter temperatures over time, followed by sudden emergence of a large and violent mud volcano. Both the 1985 and recent thermal features had similar fluid compositions.

During 1992-94 the unnamed thermal area W of Astringent Creek developed a series of seven large craters that evolved as the Mushpots thermal area did in 1985. The craters were progressively younger towards the SW, ending at the site of the current new hot ground and fumarole (figure 4). In December 1993, National Park Service research geologist R. Hutchinson predicted that the newest superheated fumarole would soon evolve into a large mud volcano.

Figure (see Caption) Figure 4. Sketch map (scale approximate) showing the surface expression of an unnamed thermal area W of Astringent Creek in Yellowstone Caldera. Coordinates for map's center are at about 44°38'06"N, 110°16'44"W. Courtesy of R. Hutchinson.

As a part of routine monitoring, the thermal area W of Astringent Creek was inspected on 7 June 1995. The former 104.3°C fumarole was replaced by a large vigorous mud pot with ejecta extensively scattered around it. In addition, two new smaller roaring fumaroles at or slightly above boiling point, three new moderate-sized churning caldrons (pits containing hot, agitated aqueous fluids), numerous smaller muddy pools, collapse pits, and frying-pan springs (audibly degassing springs) were apparent then. Extensive areas of unstable quicksand-like saturated ground made up of scalding mud were found under the fallen trees. Some regions were heavily encrusted with sulfate minerals or sulfur crystals; others were covered by baked organic matter on the pine forest's floor.

Extending NW from the largest parasitic churning caldron, below the new mud volcano crater, was a spectacular white kaoline clay mud flow (figure 4, dark shading and arrow showing flow direction). It spread rapidly to reach an average width of 13.8 m in the first 55 meters of its length in dead forest grove and eventually terminated 114 m from its source on the open, acid thermal-basin floor.

The relative freshness of the ejected mud and incorporated semi-coarse sandy material indicated that the super-heated fumarole transformed into the powerful mud volcano between mid-April and mid-May. The distribution of large mud bombs suggested that their trajectories reached 20-30 m above the crater rim. Ejecta were seen along the following compass bearings with the stated maximum distances from the crater: N, 13.6 m; E, 30.2 m; S, 25.4 m; and W, 12.1 m.

When visited on both 7 June and 9 September, the mud volcano still continued to throw mud 0.5-1.5 m high from dozens of points around the crater floor. The mud volcano crater was 13.5-m long, 11.3-m wide, and 3.9-4.9 m deep. A conservative estimate of the crater volume was 315 m3. The total area covered by the ejecta and crater was ~2,100 m2. In the SW quarter of the crater a large, slightly elevated projection was visible with an arcuate line of dry, white, probably super-heated fumarole vents.

The largest parasitic caldron had numerous points of ebullition in its irregularly shaped pool (maximum dimensions of 10.8 x 7.9 m), with a water level 0.7-1.4 m below the former forest floor. The churning water was near boiling, opaque, light tan in color, and partially covered with brown organic-rich foam derived from cooked plant material.

Each of the caldrons were interpreted as being parasitic to the mud volcano crater because they appeared to have evolved shortly after the initial fumarole collapse and then subsequently drained much of its fluids. This relationship seems to have rapidly lowered the crater floor, preventing the accumulation of a thick ejecta cone on the crater rim.

The mud volcano crater, parasitic features, vents, and the associated hot ground remain extremely dangerous and unstable. Additional alterations in the creation of new or enlarged springs, and perhaps even another mud volcano crater are anticipated. With respect to geologic hazards, the acid sulfate thermal area should be checked again in the near future. Photographs were taken on 7 June.

The Yellowstone Plateau volcanic field developed through three volcanic cycles spanning two million years and included some of the world's largest known eruptions. Eruption of the > 2,500 km3 Huckleberry Ridge Tuff ~2.1 million years ago (Ma) created a caldera more than 75 km long. The Mesa Falls Tuff erupted around 1.3 Ma, forming the 25-km-wide Island Park Caldera at the first caldera's W end. A 0.6 Ma eruption deposited the 1,000 km3 Lava Creek Tuff and associated caldera collapse created the rest of the present 45 x 75 km caldera (figure 3). Resurgent doming then occurred; voluminous (1,000 km3) intercaldera rhyolitic lava flows were erupted between 150,000 and 70,000 years ago. Phreatic eruptions produced local tephra layers during the early Holocene. Distinctive geysers, mud pots, hot springs, and other hydrothermal features within Yellowstone caldera helped lead to the establishment of the National Park in 1872.

Information Contacts: Roderick A. Hutchinson, National Park Service, P.O. Box 168, Yellowstone National Park, Wyoming 82190, USA.


September 1999 (BGVN 24:09) Citation IconCite this Report


Earthquake swarm during June along mapped faults

A series of earthquake swarms began along the NW edge of Yellowstone National Park on the evening of 13 June 1999. Between 13 and 22 June over 630 earthquakes were recorded in a region ~13 km NE of the town of West Yellowstone, Montana and ~5 km SE of Grayling Creek Junction, Montana. The largest of the earthquakes, M 3.5, occurred at 1038 on 16 June. No residents reported noticing the earthquakes. The activity was located along mapped faults that extend eastward from the S end of 1959 Hebgen Lake rupture (the 7.5 magnitude Hebgen Lake earthquake was the largest in the history of the Intermountain region). Earthquake swarms are common in Yellowstone, but this was the largest since June 1997. That swarm also occurred along the NW edge of the park, the area that historically records the most persistent swarms. The most extensive recorded earthquake swarm occurred ~10 km SE of the June activity over a period of several months in 1985 and 1986.

Seismicity in the Yellowstone region is recorded by 22 University of Utah Seismograph Stations and two Global Positioning System stations. The telemetered surveillance system provides coverage for both earthquakes and ground movement related to volcanic or earthquake activity. The project is conducted cooperatively with the U.S. Geological Survey Volcano Hazards Program and the National Park Service.

As discussed by Robert B. Smith on his web pages at the University of Utah, Yellowstone National Park is located on a hotspot within the North American Plate; its three calderas are the most recent in a string that extends to the SW across Idaho. Dubbed "The Restless Giant" for its geological instability, Yellowstone could one day have another major eruption like the one that formed its youngest caldera 600,000 years ago. Symptoms include numerous earthquakes (most too small to be felt), uplift and subsidence of the ground surface, and persistent hydrothermal activity. The current rates of seismicity, ground deformation, and hydrothermal activity at Yellowstone, although high by most geologic standards, are probably typical of long time periods between eruptions and therefore not a reason for immediate concern. Scientists from the U.S. Geological Survey and the University of Utah are studying the Yellowstone region to assess the potential hazards from future earthquakes and eruptions and to provide warning if the current level of unrest should intensify.

Information Contacts: U.S. Geological Survey, Cascades Volcano Observatory, 5400 MacArthur Blvd., Vancouver, WA 98661 USA (Email: cvo@mailvan.wr.usgs. gov, URL: http://vulcan.wr.usgs.gov); Michael Finley, Tom Deutch, and Anne Deutch, National Park Service, P.O. Box 168, Yellowstone, WY 82190 USA (Email: YELL_Superintendent@nps.gov, URL: http://www.nps.gov/yell/); Robert B. Smith, Department of Geology and Geophysics, 135 S. 1460 East, Room 702, University of Utah, Salt Lake City, UT 84112 USA (Email: rbsmith@mines.utah.edu, URL: http://www.mines.utah.edu/~rbsmith/research.html).


May 2000 (BGVN 25:05) Citation IconCite this Report


On 2 May powerful Steamboat geyser discharged over 190 m3 of water

Yellowstone's Norris basin (White and others, 1988) includes the powerful but erratic Steamboat geyser. Steamboat suddenly ejected a vigorous plume of boiling water and steam on the morning of 2 May 2000. For 9 years prior to this-since 2 October 1991-it ejected only modest water discharges to heights under 20 m. This report discusses the basic observations surrounding the outburst, the minimum volume of the water discharged, and some collateral changes seen at neighboring Cistern Spring.

Shaken campers. Around 0700, National Park Service (NPS) employee Bob Lindstrom stopped at Norris to investigate an anomalously tall vapor column. Two park visitors, who had spent the night sleeping in their camper pickup truck in the otherwise deserted Norris parking area (figure 5), told him that they were abruptly awakened about 0500. The campers had felt the ground trembling as their truck started rocking, an effect they mistook for an earthquake. Frightened, they initially drove away, but upon looking back they saw a huge vapor plume and returned to Norris.

Figure (see Caption) Figure 5. A map of Yellowstone's Norris basin showing the location of Steamboat and Echinus geysers, and Cistern Spring. The map also illustrates the parking lot where the campers spent the night of 1-2 May 2000, and the location of the instrumented weir used to estimate the runoff from Steamboat geyser's abnormally large discharge on 2 May. The map was provided by the Spatial Analysis Center, Yellowstone National Park.

By 0700 when Lindstrom arrived, a wet mist enveloped most of the area around Steamboat geyser; it appeared as local rainfall, even though elsewhere the sky remained blue. The subfreezing air temperature caused ice to form where water fell on the boardwalks running out to the geysers. Discharging steam emitted a jet-engine-like roar. Steamboat was in full steam phase, with a vapor plume then approximately 150 m tall. Although the campers took early photos not yet available to the Park, other photos were taken during the steam phase of the outburst (figure 6). The loud roaring associated with the steam phase continued unabated through at least 0800 and other sources said noises remained audible at 1100 on 2 May. According to Paul Strasser, the outburst left rocks and sand on atop the bridge over the eastern runoff channel at the base of the hill.

Figure (see Caption) Figure 6. A photo showing the steam-dominated secondary phase of the large 2 May discharge from Yellowstone's Steamboat geyser. More photos of the steam phase are available at the web site given below. The exact time of the photo and the location of the photographer remain unreported. National Park Service photo by Tom Cawley.

Water runoff. To study changes in the Norris basin, for the past 12 years Irving Friedman has monitored the output of a small creek that drains the basin, ~2 km from Steamboat and Echinus geysers (Tantalus creek, figure 5). His efforts have been substantively aided by NPS support and collaboration in addition to help from a cadre of volunteers.

Tantalus creek's discharge gets measured at a small dam with a notch of known dimension (a weir). The height of the water passing through the weir relates to the stream discharge. The water height gets measured by a float gauge similar to those in automobile fuel tanks. The float's position gets recorded every 10 minutes by a data logger. The 10-minute sampling rate means that the instrumentation can only be expected to reflect behavior with periods over 20 minutes; signal processing theory suggests shorter processes can be aliased (i.e., biased leading to misleading results). Since each of the outburst's two phases each lasted over an hour, the sampling interval appears to have been adequate to describe the two phases.

As shown on figure 7, the 1 and 2 May weir data show runoff changing in a long-period cycle somewhat over 20 hours in length, with the Steamboat peak on 2 May superimposed on or near the peak of this long-period cycle. Similar long-period runoff cycles occur often in the weir data, but their cause has not been identified.

Figure (see Caption) Figure 7. A plot showing the time-series of water discharge from Yellowstone's Norris basin on 1 and 2 May as measured at the weir. The position of the weir's float gauge was recorded every 10 minutes. Courtesy of Irving Friedman.

The weir data on 1 May and during parts of 2 May showed the typical behavior seen in the basin, in this case with Echinus runoff producing repeated peaks with a range of 0.5-1.7 hours and a mean of ~1.1 hours. Ignoring the interval where the Echinus data became masked by the much larger Steamboat peak, the weir data on 2 May was similarly dominated by Echinus runoff; in this case showing peaks with a range of 0.5-3 hours and a mean of ~1.1 hours.

The strong 2 May discharge at Steamboat furnished runoff that arrived at the weir at about 0520 (figure 7). Friedman estimated that the travel time for water from Steamboat to the measuring weir to be about 20 to 30 minutes, so the outburst must have occurred at about 0500. Within the limitations of the instrumental data at the weir, the discharge reached its apex at 0600.

The water phase of the outburst lasted 40 to 60 minutes, reaching a recorded peak discharge rate of ~10 m3 per minute.

The total amount of water discharged during the outburst can be calculated, giving a minimum estimate of the discharge during the outburst. The calculation was made using the area under the curve from the assumed base flow (figure 7).

In addition, figure 7 shows how Friedman broke the Steamboat outburst into a water-dominated phase and a later steam-dominated phase. For the water phase, the weir discharged ~150 m3 (150,000 Liters); for the steam-phase, ~36 m3 (36,000 ,. In addition to the measured runoff, a large, but unknown amount of steam and condensate escaped into the atmosphere; other losses included water stored in places such as soil, ponded on the surface, etc.

Friedman also discusses several representative day-long intervals of weir data, such as 21 September 1998, a day when small but regular peaks of ~0.4 m3/s occurred almost hourly, caused by the outbursts at Echinus geyser. Similar, though less regular patterns persisted in some of the later data. Unfortunately, an electrical connection corroded and broke electrical continuity, halting data collection during the interval early February-May 1999.

During this interval without instrumental record, changes occurred at Norris: a) approximately 1 km from Echinus a new thermal area emerged; b) Echinus's period between outbursts became less regular; and c) the outbursts varied in duration and size, sometimes becoming absent from the record. It is possible that this emergent thermal area robbed Echinus of some of its water and heat. How or whether this helped drive Steamboat towards its 2 May outburst remains uncertain.

Collateral observations. NPS literature states that Cistern Spring's water supply has been closely associated with Steamboat geyser: "When Steamboat erupts, Cistern Spring slowly drains." This pattern prevailed in the 2 May outburst. At 1100 on 2 May the surface water in Cistern Spring was ~8 cm below overflow. By 1900 on 2 May, it had dropped by 1.2 m. By 0900 on 3 May, Cistern Spring was empty; a photo around that time showed Steamboat's continuing steam phase with a plume tens of meters tall.

In reporting recent geyser news on the Geyser Observation and Study Association (GOSA) web page, Paul Strasser noted that eight days prior to the minor outbursts, water gushed mainly from Steamboat's S vent, but occasionally gushed at its N vent, a pattern similar to the mode of activity seen last year. Strasser also noted some possible precursory effects. After the outburst, visitors allegedly told NPS staff that on 29 and 30 April they had seen water from both vents reaching 12-18 m high and felt a larger outburst might start.

Naturalist John Tebby told Strasser that on 1 May he saw the minor discharges starting from both of Steamboat's vents, but only to ~2 m high; a modest amount of runoff came from the S vent. He was only in the vicinity for a short time. Intriguingly, Cistern Spring was then in heavy boil to depths of 15-20 cm, apparently having heated up.

Background. The following comes from GOSA's descriptive list of Yellowstone's 182 geysers: "Steamboat Geyser is currently the tallest geyser in the world. Its major eruptions [discharges] can soar to nearly 400 feet [120 m]. Unfortunately, its major eruptions [discharges] are rare and erratic. Intervals between majors have ranged from 4 days to 50 years. More common is its minor activity that consists of splashes or small discharges every few minutes. This minor play can reach 30 feet [9 m] or more."

"Steamboat is a cone-type geyser erupting [discharging] from two main vents. The water phase of a major eruption [outburst] lasts from 3 to 20 minutes and is followed by an extremely loud steam phase that can continue for another 12 hours. The water phase emits a large amount of water. The aftermath of which can easily be seen around the geyser . . . [sound intensity] of the steam phase has been described as painful . . . [audible] miles away."

According to the Yellowstone Public Affairs office, Steamboat was dormant from 1911-1961. In recent years, Steamboat has had major discharges in 1989 (three events), 1990 (one event), and 1991 (one event).

Strasser discusses how during 1982-84 Steamboat produced numerous short-interval minor discharges, whereas during 1979 only one outburst took place. Strasser and others (1989) cite more references than shown here.

References. Whittlesey, Lee, 2000, Full steam ahead: Steamboat Geyser erupts!: The Buffalo Chip (a Yellowstone National Park employee resource-management newsletter) (Spring, 2000).

Strasser, P., Strasser, S., and Pulliam, B., 1989, Investigations of patterns of minor behavior of Steamboat geyser, 1982-1984: Geyer Observation and Study Association Transactions, v. 2, p. 43-70 (see GOSA website).

White, D.E., Hutchinson, R.A., and Smith, T.E.C., 1988, The geology and remarkable thermal activity of Norris Geyser Basin, Yellowstone National Park, Wyoming: U.S. Geological Survey Professional Paper 1456, U.S. Government Printing Office.

Information Contacts: Bob Lindstrom and Ann Rodman, Yellowstone National Park, Wyoming 82190 USA (Email: bob_lindstrom@nps.gov; ann_rodman@nps.gov); Irving Friedman, U.S. Geological Survey, P.O. Box 25046, MS 963, Denver, CO 80225 USA (Email: friedman@usgs.gov); Geyser Observation and Study Association (GOSA), care of Janet & Udo Freund, 39237 Yellowstone St., Palmdale, CA 93551 USA (URL: http://www.geyserstudy.org/geyser_main.htm).


July 2003 (BGVN 28:07) Citation IconCite this Report


Geyser basin heats up, affecting thermal features

Yellowstone National Park press releases indicated unusual hydrothermal activity at the Norris geyser basin in the NW-central portion of the Park. A press release on 22 July 2003 announced that high ground temperatures and increased thermal activity had resulted in the temporary closure of a portion of the Back Basin.

The press release noted "Norris is the hottest and most seismically active geyser basin in Yellowstone. Recent activity in the Norris geyser basin has included formation of new mud pots, an eruption of Porkchop geyser (dormant since 1989), the draining of several geysers, creating steam vents and significantly increased measured ground temperatures (up to 200°F [93°C]). Additional observations include vegetation dying due to thermal activity and the changing of several geysers' eruption intervals. Vixen geyser has become more frequent and Echinus geyser has become more regular."

A press release on 7 August advised of a hydrothermal monitoring program by the Yellowstone Volcano Observatory to begin at Norris geyser basin. The Observatory is a collaborative partnership between the US Geological Survey, the University of Utah, and Yellowstone National Park. It was deploying a temporary network of seismographs, Global Positioning System receivers, and temperature loggers. Goals included identification of hydrothermal steam sources, the relationship of the behavior of Norris geyser basin to the general seismicity, and locating crustal deformation in the caldera.

Information Contacts: Yellowstone Volcano Observatory, a cooperative arrangement that includes Robert L. Christiansen, U.S. Geological Survey, 345 Middlefield Road, Menlo Park, CA 94025; Robert B. Smith, Department of Geology and Geophysics, University of Utah, Salt Lake City, Utah 84112 USA; Henry Heasler, National Park Service, P.O. Box 168, Yellowstone National Park, WY 82190-0168 USA; and others (URL: www.volcanoes.usgs.gov/yvo/yvo/html/).


February 2006 (BGVN 31:02) Citation IconCite this Report


Low seismicity; ongoing ground-surface deformation

According to the Yellowstone Volcano Observatory (YVO), during February 2006 there was relatively low seismicity, with 82 reported earthquakes in the region. The largest of these was on 25 February, M 3.1, located near the N caldera rim (~ 10 km SSW of Canyon Junction). None of these earthquakes were reported as felt. Our previous report discussed elevated temperatures of the ground and increased hydrothermal effects at Norris hot springs in 2003 (BGVN 28:07). Norris also represents a frequent epicentral area for earthquakes inside the caldera. In 2002, for example, there were more than 2,350 earthquakes detected at Yellowstone, including over 500 triggered by the November 2002, M 7.9 Denali earthquake. Seismicity during April 2005-April 2006 was comparatively low. Figure 8 plots quarterly earthquakes (≥ M 1.5) during 1974-2004 on a histogram. Figure 9 depicts earthquake swarms during 1985, 1995, and 2004.

Figure (see Caption) Figure 8. A plot of recorded earthquakes (≥ M 1.5) at Yellowstone from 1974 through 2004 (bars, left-hand scale: each bar represents the sum of the earthquakes of stated size per quarter (~ 90 days)). The curving solid line shows the cumulative number of earthquakes for the thirty-year period (right-hand scale). Estimates of mean caldera uplift and subsidence are shown as a dashed-and-dotted line with no scale. Note that this figure stopped in 2004 and does not depict some of the stronger deformation seen in radar and later GPS data (discussed below). Courtesy of YVO (after a figure by Waite and Smith, 2002).
Figure (see Caption) Figure 9. A map of Yellowstone caldera and National Park with circles indicating located earthquakes (≥ M 1.5) from the swarm of 1985 (westerly cluster), 1995 (easterly cluster with substantial events inside the caldera), and 2004 (smaller cluster to the N of the other two). Courtesy of YVO.

Satellite radar created an interferogram of the caldera region (basically, a depiction of the vertical offset determined by satellite radar during 1996-2000). The interferogram portrayed vertical displacement as a large bull's-eye shape (figure 10), and indicated 12.5 cm of uplift centered in the northern portion of the caldera ~ 25 km NW of Yellowstone Lake.

Figure (see Caption) Figure 10. A radar interferogram of the Yellowstone caldera region (after Wicks and others, 1998; 2006). This image of vertical ground deformation was created using data from several satellite passes during 1996 through 2000. The image shows 12.5 cm of uplift centered within the northern end of Yellowstone caldera (black dotted line), about 10 km S of Norris hot springs. Each full spectrum of color (from red to purple) represents ~ 28 mm of uplift. The area of uplift is approximately 35 km x 40 km in size. Courtesy of YVO-USGS.

In response to increased heat and steam emissions in parts of Norris geyser basin, a temporary, five-station GPS network was installed in that area in 2003. The network was installed by a UNAVCO engineer, University of Utah students and faculty, and National Park Service scientists as part of a monitoring effort by YVO. Permanent station NRWY currently resides there (figure 11).

Figure (see Caption) Figure 11. GPS stations at Yellowstone caldera, including those both existing (light triangles) and planned (dark triangles). The irregular loops near stations OFW2 and WLWY outline the two active resurgent domes within the 0.64 million-year-old Yellowstone caldera (the Mallard Lake dome and the Sour Creek dome, to the W and E, respectively). The figure also includes Yellowstone caldera topographic margins (T), Yellowstone Lake (L), the National Park boundary (PB), and some state boundaries. Courtesy of YVO-USGS.

Movement near the N end of Yellowstone Lake was measured by GPS at station LKWY during 1997 to late 2005 (figure 12). The N-S movement (top panel) shown in the past year consisted of displacement of 10-15 mm southward. This N-S movement was somewhat stronger and more protracted than in the earlier parts of the GPS data. The E-W movement (middle panel) was comparatively steady and unbroken over the past 6 years or more, directed westward. Over the past 9 years, the overall E-W motion was ~ 15 mm westward. The vertical motion (lower panel) was negative (subsidence) during 1997 to mid-2004. After that, station LKWY moved sharply upward, rising ~ 80 mm in the last year and a half. Caldera systems frequently undergo ground displacements similar to those observed at Yellowstone without progressing to eruptive activity.

Figure (see Caption) Figure 12. Relative movement of GPS station LKWY (located in the central part of the caldera, at the N end of Yellowstone Lake) recorded during 1997 to late 2005. The top panel shows N-S movement, the middle, E-W movement, and the bottom, vertical movement. During 2001-2004 station LKSY moved downward (subsided) on the order of 20 mm. After mid-2004, LKWY moved upward ~ 80 mm. Courtesy of YVO-USGS.

Much of the history of older calderas that preceded Yellowstone are buried in the subsurface to the W, and a drilling proposal for that region is under development. "Hotspot," the Snake River Scientific Drilling Project, announced an inter-disciplinary workshop with that goal, to be held 18-21 May 2006 and focused on issues central to a new intermediate-depth drilling program in the Snake River Plain of S Idaho, USA. That region provides a record of inferred mantle plume volcanism in an intra-continental setting. Because it is young and tectonically undisturbed, the complete record of volcanic activity can be sampled only by drilling. The preliminary plan was to drill and core 4-6 holes along the axis of the E and W Snake River Plain.

References. Wicks, C., Thatcher, W., and Dzurisin, D., 1998, Migration of fluids beneath Yellowstone Caldera inferred from satellite radar interferometry: Science, v. 282, p. 458-462.

Wicks, C., Thatcher, W., Dzurisin, D., and Svarc, J., 2006 (in press), Uplift, thermal unrest, and magma intrusion at Yellowstone Caldera, observed with InSAR: Nature.

Waite, G.P., and Smith, R.B.,

Information Contacts: Yellowstone Volcano Observatory, a cooperative arrangement that includes Jacob B. Lowenstern, U.S. Geological Survey, 345 Middlefield Road, Menlo Park, CA 94025, USA; Robert B. Smith, Department of Geology and Geophysics, University of Utah, Salt Lake City, UT 84112, USA; Henry Heasler, National Park Service, P.O. Box 168, Yellowstone National Park, WY 82190-0168, USA (URL: http://volcanoes.usgs.gov/yvo/).


February 2010 (BGVN 35:02) Citation IconCite this Report


Second largest recorded earthquake swarm during January-February 2010

Monthly updates from the Yellowstone Volcano Observatory (YVO) summarize seismic activity (table 1) and ground deformation at Yellowstone caldera. Earthquake activity remained at low levels during the majority of the reporting interval (November 2006 through February 2010). There were several earthquake swarms during this time, including significant events in December 2008-January 2009 and January-February 2010. The early 2010 events comprised the second largest earthquake swarm recorded at Yellowstone, second only to the fall 1985 swarm (BGVN 17:03). The swarm that began in December 2008 was the third largest swarm recorded.

Table 1. Seismic data for Yellowstone organized by month, including the number of recorded earthquakes, the largest magnitude recorded, and earthquake swarm information. Note the large swarms during December 2008-January 2009 and during January-February 2010. Data courtesy of the USGS.

[Skip text table]
    Month        Number of     Largest magnitude    Earthquake swarms
                earthquakes                         dates (number of events)

    Nov 2006         87          2.7 on 04 Nov      04-07 Nov (47)
    Dec 2006         36          2.0 on 16 Dec      --
    Jan 2007         93          2.8 on 30 Jan      --
    Feb 2007        113          2.9 on 27 Feb      27-28 Feb (5); 13-22 Feb (59)
    Mar 2007         63          2.3 on 21 Mar      11 on 1 Mar
    Apr 2007         53          2.1 on 22 Apr      --
    May 2007         59          2.7 on 01 May      01 May (14)
    Jun 2007         73          1.5 on 27 Jun      20 June (26)
    Jul 2007         80          2.2 on 26 Jul      --
    Aug 2007         74          2.8 on 03 Aug      19-21 Aug ("small" event)
    Sep 2007         54          2.3 on 10 Sep      --
    Oct 2007         34          2.1 on 17 Oct      --
    Nov 2007         69          2.9 on 04 Nov      --
    Dec 2007        184          3.6 on 30 Dec      18-21 Dec (48)
    Jan 2008        263          3.7 on 09 Jan      09 Jan (124); 25-26 Jan (32)
    Feb 2008        130          2.4 on 03 Feb      03 Feb (47)
    Mar 2008        147          4.2 on 25 Mar      11-16 Mar (73); 21-22 Mar (17)
    Apr 2008         70          1.7 on 17 Apr      --
    May 2008         99          2.3 on 18 May      04-14 May (37)
    Jun 2008         79          2.7 on 04 Jun      04-08 Jun (27)
    Jul 2008        185          2.5 on 31 Jul      28-31 Jul (132)
    Aug 2008        146          2.3 on 31 Aug      01-05 Aug (52); 03-07 Aug (28);
                                                      07-08 Aug (32)
    Sep 2008         62          2.9 on 25 Sep      25 Sep (19)
    Oct 2008         46          2.4 on 05 Oct      --
    Nov 2008        166          2.7 on 23 Nov      23-29 Nov (77)
    Dec 2008       ~500          3.9 on 27 Dec      27 Dec-05 Jan (~ 813)
    Jan 2009        315          3.5 on 02 Jan      09-12 Jan (35)
    Feb 2009         51          2.1 on 19 Feb      --
    Mar 2009         66          2.4 on 03 Mar      --
    Apr 2009        242          2.7 on 28 Apr      13-18 Apr (62); 17-25 Apr (111);
                                                      29 Apr (19)
    May 2009        133          3.0 on 25 May      25 May (68)
    Jun 2009         77          3.3 on 30 Jun      30 Jun (25)
    Jul 2009         98          2.7 on 08 Jul      01-03 Jul (12)
    Aug 2009         86          2.1 on 14 Aug      08-12 Aug (29)
    Sep 2009        177          2.3 on 20 Sep      12-17 Sep (39); 13-18 Sep (66)
    Oct 2009        218          2.5 on 15 Oct      12-23 Oct (138)
    Nov 2009         69          3.1 on 09 Nov      --
    Dec 2009         70          2.2 on 18 Dec      --
    Jan 2010       1620          3.8 on 20 Jan      17 Jan-25 Feb (1,809)
    Feb 2010        244          3.1 on 02 Feb      --

Earthquake swarm, December 2008-January 2009. An earthquake swarm from 26 December 2008 to 5 January 2009 was centered beneath the N end of Yellowstone Lake. The event consisted of ~ 900 earthquakes with magnitudes ranging up to 3.9; 19 events had magnitudes greater than 3.0, while 141 had magnitudes between 2.0 and 2.9.

Earthquake swarm, January-February 2010. The January-February 2010 earthquake swarm was centered about 16 km NW of Old Faithful, on the NW edge of the caldera. The event began with a few small earthquakes on 15 January and began to intensify on 17 January. A 3.7 magnitude earthquake was recorded at 2301 on 20 January, followed by a magnitude 3.8 event at 2316. The events were felt throughout the park and surrounding communities in Wyoming, Montana, and Idaho. By 25 February, YVO had recorded a total of 1,809 earthquakes, with 14 reaching magnitudes of over 3.0 and 136 with magnitudes between 2.0 and 2.9. By the end of February activity had returned to background levels.

The University of Utah Seismology Research Group stated that the total seismic energy released by all the earthquakes in this swarm corresponded to one earthquake with an approximate magnitude of 4.4. YVO emphasized that while this was an unusually large event, it did not indicate premonitory volcanic or hydrothermal activity. Rather, the swarm earthquakes were likely the result of slip on pre-existing faults.

Information Contacts: Yellowstone Volcano Observatory, U.S. Geological Survey, 345 Middlefield Road, Menlo Park, CA 94025, USA (URL: http://volcanoes.usgs.gov/yvo/).

Eruptive History


Summary of Holocene eruption dates and Volcanic Explosivity Indices (VEI).


Start Date Stop Date Eruption Certainty VEI Evidence Activity Area or Unit
1350 BCE ± 200 years Unknown Confirmed   Radiocarbon (corrected) Indian Pond crater (N of Yellowstone Lake)
3050 BCE (?) Unknown Confirmed   Tephrochronology Duck Lake, Evil Twin Craters (West Thumb)
6050 BCE (?) Unknown Confirmed   Tephrochronology Elliott's Crater (Yellowstone Lake)
7400 BCE ± 860 years Unknown Confirmed   Radiocarbon (corrected) Turbid Lake (NE of Yellowstone Lake)

This compilation of synonyms and subsidiary features may not be comprehensive. Features are organized into four major categories: Cones, Craters, Domes, and Thermal Features. Synonyms of features appear indented below the primary name. In some cases additional feature type, elevation, or location details are provided.

Photo Gallery


The terraces of Mammoth Hot Springs in NW Yellowstone consist of shallow pools with ledges draped with ribbons of travertine. Rapid deposition encroaches on nearby forests and can produce changes visible within a period of weeks.

Photo by Lee Siebert, 1968 (Smithsonian Institution).
See title for photo information.
An eruption of Old Faithful, perhaps the world's best known geyser, rises above Yellowstone's Upper Geyser Basin. Old Faithful is a periodic geyser, with eruptions to heights of about 40 m at intervals of 30 to 100 minutes. Old Faithful Lodge to the right provides a rustic backdrop to the Upper Geyser Basin, which contains more geysers than are known altogether in the rest of the world. The forested ridge in the background is underlain by massive post-caldera rhyolitic lava flows of the Madison Plateau.

Photo by Lee Siebert, 1968 (Smithsonian Institution).
See title for photo information.
The West Thumb Geyser Basin at the SW end of Yellowstone Lake contains thermal features, such as this sinter mound, both above and below the lake shore. The West Thumb embayment of Yellowstone Lake is a smaller caldera that formed as a result of an explosive eruption during a period of mainly lava-producing eruptions during the past 150,000 years.

Photo by Lee Siebert, 1994 (Smithsonian Institution).
See title for photo information.
The thick cliffs are composed of massive ash-flow deposits of the Lava Creek Tuff, erupted about 640,000 years ago. Eruption of the 1000 cu km Lava Creek Tuff resulted in the formation of the present 45 x 85 km wide caldera, the latest of three large calderas formed at Yellowstone during the past 2 million years.

Photo by Lee Siebert, 1994 (Smithsonian Institution).
See title for photo information.
The Mesa Falls Tuff is exposed in a quarry wall near Ashton, Idaho that shows light-colored airfall and pyroclastic-surge deposits overlain by orange-colored pyroclastic-flow deposits. The 280 cu km Mesa Falls Tuff, deposited about 1.3 million years ago during the second of Yellowstone's three largest eruptions, resulted in the formation of the 16-km-wide Henrys Fork caldera west of Yellowstone National Park.

Photo by Lee Siebert, 1994 (Smithsonian Institution).
See title for photo information.
A small mudpot vent in Pocket Basin at the north end of Yellowstone's Lower Geyser Basin produced this intriguing feature that mimics a spatter cone that issued a lava flow. Mudpots form in areas of intense, clay-rich hydrothermal alteration where the thermal system is dominated by the gas phase.

Photo by Dan Dzurisin, 1983 (U.S. Geological Survey).
See title for photo information.
The two dark horizontal bands in the cliff on the left near Tower Junction in NE Yellowstone are lava flows that display prominent columnar jointing. The base of the cliff exposes volcanic materials of the Absaroka Formation. The light-colored rocks between the basaltic lava flows are stream-gravel sediments. The top of the hill consists of lake sediments.

Photo by Dan Dzurisin, 1983 (U.S. Geological Survey).
See title for photo information.
The tip of Yellowstone Lake is seen at the upper left from Pelican Cone near the NE rim of Yellowstone caldera. The forested, snow-capped peaks in the center are rocks of the Sour Creek resurgent dome, an area of uplifted and faulted post-caldera rocks.

Photo by Dzurisin, 1985 (U.S. Geological Survey).
See title for photo information.
Bison graze in a meadow along the Madison River in front of rocks of the massive West Yellowstone lava flow that are visible in the cliff behind them as a result of the 1988 Yellowstone fires.

Photo by Lee Siebert, 1994 (Smithsonian Institution).
See title for photo information.
A roadcut at Golden Gate, north of Mammoth, cuts through the Huckleberry Ridge Tuff, the deposit produced by the gigantic eruption that created Yellowstone's first caldera about 2 million years ago. The 2500 cu km Huckleberry Tuff, one of the world's largest Quaternary eruptions, consists of welded tuffs and voluminous airfall deposits found as far away as southern California. The eruption created the 75-km-wide Island Park caldera, which extends from SE-Idaho into central Yellowstone.

Photo by Lee Siebert, 1994 (Smithsonian Institution).
See title for photo information.
Riverside Geyser in the Upper Geyser Basin is the most regular of Yellowstone's geysers. Every six hours it erupts a 25-m-high inclined jet from a small vent hole on the east bank of the Firehole River 2 km downstream from Old Faithful.

Photo by Lee Siebert, 1968 (Smithsonian Institution).
See title for photo information.
The Yellowstone River slowly meanders through the Hayden Valley, which is underlain by glacial lake sediments capping thick lava flows on the floor of Yellowstone caldera. Mount Washburn, in the center background, is part of an ancient Absaroka volcano that predates the caldera. The northern margin of the Yellowstone caldera lies at the base of the mountain range.

Photo by Lee Siebert, 1974 (Smithsonian Institution).
See title for photo information.
The 500-m-wide Indian Pond hydrothermal explosion crater immediately north of the NE shore of Yellowstone Lake formed about 3350 years ago. Deposits from this eruption extend 3 km from the crater and are up to 3-4 m thick. Yellowstone Lake is seen at the top, with the highway leading to Cody at the bottom in this aerial view from the NE.

Photo by Jim Peaco, 2001 (National Park Service).
See title for photo information.

Smithsonian Sample Collections Database


The following 1259 samples associated with this volcano can be found in the Smithsonian's NMNH Department of Mineral Sciences collections. Catalog number links will open a window with more information.

Catalog Number Sample Description
NMNH 10569 Obsidian
NMNH 10570 Hyalo liparite
NMNH 10574-1 Hyalo liparite
NMNH 10574-2 Hyalo liparite
NMNH 111123-23 Siliceous sinter
NMNH 111123-62 Lithoidite
NMNH 111123-63 Rhyolite
NMNH 111123-94 Diorite
NMNH 116281 Glassy tuff
NMNH 116282 Perlite
NMNH 28913 Obsidian
NMNH 28914 Hyalo liparite
NMNH 28917 Hyalo liparite
NMNH 28921 Hyalo liparite
NMNH 28923 Hyalo liparite
NMNH 28975 Hyalo liparite
NMNH 29106 Hyalo liparite
NMNH 62041-1 Obsidian
NMNH 62041-2 Obsidian
NMNH 72854 Rhyolite glass
NMNH 72854 Obsidian
NMNH 72854 Obsidian
NMNH 72854-1 Obsidian
NMNH 72854-2 Obsidian
NMNH 72855 Obsidian
NMNH 74116 Obsidian
NMNH 88788 Obsidian
NMNH 88788 Obsidian
NMNH 88788-1 Obsidian
NMNH 88788-3 Obsidian
NMNH 91322-100 Kersantite
NMNH 91322-102 Dacite
NMNH 91322-1024 Andesite with hornblende and pyroxene
NMNH 91322-1025 Andesite volcanic ash
NMNH 91322-1026 Andesite volcanic ash
NMNH 91322-1027 Trachytic rhyolite
NMNH 91322-1028 Trachytic rhyolite
NMNH 91322-1031 Trachytic rhyolite
NMNH 91322-1032 Andesite with hornblende and pyroxene
NMNH 91322-1038 Andesite
NMNH 91322-1041 Basalt
NMNH 91322-1043 Basalt
NMNH 91322-105 Dacite
NMNH 91322-1051 Volcanic ash
NMNH 91322-106 Dacite
NMNH 91322-1087 Breccia
NMNH 91322-1126 Basalt
NMNH 91322-1127 Shoshonite
NMNH 91322-1129 Basalt
NMNH 91322-1130 Basalt
NMNH 91322-1131 Shoshonite
NMNH 91322-1132 Basalt
NMNH 91322-1133 Basalt
NMNH 91322-1135 Shoshonite
NMNH 91322-1136 Shoshonite
NMNH 91322-1137 Shoshonite
NMNH 91322-1138 Basalt
NMNH 91322-1139 Basalt
NMNH 91322-1140 Basalt
NMNH 91322-1141 Basalt
NMNH 91322-1143 Shoshonite
NMNH 91322-1145 Basalt
NMNH 91322-1147 Shoshonite
NMNH 91322-1150 Basalt
NMNH 91322-1151 Absarokite
NMNH 91322-1152 Basalt
NMNH 91322-1153 Shoshonite
NMNH 91322-1155 Shoshonite
NMNH 91322-1157 Andesite with hornblende and mica
NMNH 91322-1158 Unidentified
NMNH 91322-1159 Unidentified
NMNH 91322-1160 Breccia
NMNH 91322-1161 Andesite
NMNH 91322-1165 Copper
NMNH 91322-1170 Andesite with hornblende and mica
NMNH 91322-1224 Quartz (var. chalcedony)
NMNH 91322-1232 Basalt
NMNH 91322-1241 Basalt glass
NMNH 91322-1245 Unidentified
NMNH 91322-1252 Basalt
NMNH 91322-1260 Basalt
NMNH 91322-1277 Absarokite
NMNH 91322-1282 Absarokite
NMNH 91322-1283 Basalt
NMNH 91322-1296 Banakite
NMNH 91322-1302 Banakite
NMNH 91322-1303 Basalt
NMNH 91322-1304 Basalt
NMNH 91322-1306 Absarokite
NMNH 91322-1307 Absarokite
NMNH 91322-1308 Absarokite
NMNH 91322-1309 Banakite
NMNH 91322-1313 Basalt
NMNH 91322-1314 Basalt
NMNH 91322-1316 Shoshonite
NMNH 91322-1317 Andesite
NMNH 91322-1318 Shoshonite
NMNH 91322-1319 Andesite with hornblende and mica
NMNH 91322-132 Andesite
NMNH 91322-1324 Basalt
NMNH 91322-1325 Basalt
NMNH 91322-1328 Shoshonite
NMNH 91322-134 Andesite
NMNH 91322-1343 Basalt
NMNH 91322-1344 Shoshonite
NMNH 91322-1353 Basalt
NMNH 91322-1354 Shoshonite
NMNH 91322-1359 Andesite
NMNH 91322-136 Andesite
NMNH 91322-1361 Andesite
NMNH 91322-1367 Andesite with hornblende and mica
NMNH 91322-1368 Andesite with hornblende and pyroxene
NMNH 91322-1369 Andesite
NMNH 91322-1372 Andesite
NMNH 91322-1377 Andesite
NMNH 91322-1378 Andesite
NMNH 91322-1381 Andesite with hornblende and mica
NMNH 91322-1383 Gabbro
NMNH 91322-1384 Andesite with hornblende and mica
NMNH 91322-1385 Andesite
NMNH 91322-1386 Andesite
NMNH 91322-1387 Diorite with mica and pyroxene
NMNH 91322-1388 Gabbro
NMNH 91322-1389 Gabbro
NMNH 91322-1390 Gabbro
NMNH 91322-1391 Gabbro
NMNH 91322-1392 Gabbro
NMNH 91322-1393 Gabbro
NMNH 91322-1394 Gabbro
NMNH 91322-1395 Gabbro
NMNH 91322-1396 Diorite-gabbro with mica and orthoclase
NMNH 91322-1397 Gabbro
NMNH 91322-1398 Gabbro
NMNH 91322-1399 Diorite-gabbro with mica and orthoclase
NMNH 91322-140 Andesite with hornblende and mica
NMNH 91322-1400 Gabbro
NMNH 91322-1401 Andesite with hornblende and mica
NMNH 91322-1405 Gabbro
NMNH 91322-1407 Gabbro
NMNH 91322-1408 Andesite with hornblende and mica
NMNH 91322-1411 Diorite
NMNH 91322-1412 Diorite
NMNH 91322-1413 Diorite
NMNH 91322-1414 Diorite
NMNH 91322-1418 Andesite
NMNH 91322-1419 Gabbro
NMNH 91322-1420 Gabbro
NMNH 91322-1421 Gabbro
NMNH 91322-1422 Dyke rock
NMNH 91322-1423 Diorite with mica and quartz
NMNH 91322-1424 Aplite
NMNH 91322-1425 Diorite with mica and quartz
NMNH 91322-1427 Diorite with mica and quartz
NMNH 91322-1428 Diorite with mica and quartz
NMNH 91322-1429 Diorite with mica and quartz
NMNH 91322-1430 Gabbro
NMNH 91322-1431 Gabbro
NMNH 91322-1436 Gabbro
NMNH 91322-1437 Diorite with biotite and hornblende
NMNH 91322-1442 Monzonite
NMNH 91322-1447 Monzonite
NMNH 91322-1448 Basalt
NMNH 91322-1449 Basalt
NMNH 91322-1455 Banakite-shoshonite
NMNH 91322-1457 Shoshonite
NMNH 91322-1459 Basalt
NMNH 91322-146 Andesite with hornblende and mica
NMNH 91322-1460 Banakite
NMNH 91322-1462 Shoshonite
NMNH 91322-1463 Andesite
NMNH 91322-1466 Banakite
NMNH 91322-1467 Banakite
NMNH 91322-1468 Shoshonite-banakite
NMNH 91322-1469 Banakite
NMNH 91322-147 Andesite with hornblende and mica
NMNH 91322-1470 Basalt
NMNH 91322-1471 Basalt
NMNH 91322-1472 Basalt
NMNH 91322-1473 Breccia
NMNH 91322-1474 Shoshonite
NMNH 91322-1475 Shoshonite
NMNH 91322-1476 Shoshonite
NMNH 91322-1477 Basalt
NMNH 91322-1478 Andesite
NMNH 91322-1479 Andesite with hornblende and pyroxene
NMNH 91322-148 Andesite with hornblende and mica
NMNH 91322-1480 Breccia
NMNH 91322-1481 Andesite with hornblende and mica
NMNH 91322-1482 Andesite with hornblende and mica
NMNH 91322-1483 Andesite with hornblende and pyroxene
NMNH 91322-1484 Breccia
NMNH 91322-1485 Andesite
NMNH 91322-1486 Breccia
NMNH 91322-1487 Breccia
NMNH 91322-1492 Andesite with hornblende and pyroxene
NMNH 91322-1497 Andesite
NMNH 91322-1498 Andesite with hornblende and pyroxene
NMNH 91322-1499 Andesite
NMNH 91322-1500 Andesite with hornblende and pyroxene
NMNH 91322-1504 Andesite
NMNH 91322-1505 Andesite volcanic ash
NMNH 91322-1506 Andesite
NMNH 91322-1507 Andesite
NMNH 91322-1509 Andesite with hornblende and mica
NMNH 91322-151 Andesite
NMNH 91322-1510 Dacite
NMNH 91322-1511 Andesite with hornblende and pyroxene
NMNH 91322-1512 Andesite with hornblende and pyroxene
NMNH 91322-1513 Andesite
NMNH 91322-1514 Andesite
NMNH 91322-1515 Andesite
NMNH 91322-1516 Andesite with hornblende and pyroxene
NMNH 91322-1521 Andesite with hornblende and pyroxene
NMNH 91322-1522 Andesite with hornblende and pyroxene
NMNH 91322-1523 Tuff
NMNH 91322-1524 Andesite
NMNH 91322-1525 Andesite
NMNH 91322-1526 Basalt
NMNH 91322-1527 Basalt
NMNH 91322-1528 Breccia
NMNH 91322-1529 Breccia
NMNH 91322-1530 Andesite
NMNH 91322-1532 Andesite with hornblende and mica
NMNH 91322-1533 Andesite with hornblende and pyroxene
NMNH 91322-1534 Andesite with hornblende and mica
NMNH 91322-1535 Andesite with hornblende and pyroxene
NMNH 91322-1536 Granite
NMNH 91322-1538 Andesite with hornblende and pyroxene
NMNH 91322-1539 Andesite with hornblende and pyroxene
NMNH 91322-1540 Andesite with hornblende and pyroxene
NMNH 91322-1541 Andesite with hornblende and pyroxene
NMNH 91322-1542 Andesite
NMNH 91322-1543 Andesite with hornblende and mica
NMNH 91322-1545 Andesite with hornblende and mica
NMNH 91322-1546 Dacite
NMNH 91322-1547 Andesite with hornblende and mica
NMNH 91322-1548 Andesite
NMNH 91322-1549 Andesite
NMNH 91322-1550 Diorite
NMNH 91322-1551 Diorite
NMNH 91322-1552 Diorite
NMNH 91322-1553 Diorite
NMNH 91322-1554 Diorite
NMNH 91322-1555 Diorite
NMNH 91322-1556 Andesite with hornblende and mica
NMNH 91322-1557 Andesite with hornblende and mica
NMNH 91322-1558 Andesite with hornblende and mica
NMNH 91322-1559 Andesite
NMNH 91322-1560 Andesite
NMNH 91322-1561 Andesite with hornblende and pyroxene
NMNH 91322-1562 Andesite
NMNH 91322-1563 Andesite
NMNH 91322-1564 Andesite
NMNH 91322-1565 Andesite
NMNH 91322-1566 Andesite
NMNH 91322-1567 Andesite
NMNH 91322-1568 Andesite
NMNH 91322-1569 Basalt
NMNH 91322-1570 Andesite with hornblende and pyroxene
NMNH 91322-1571 Andesite with hornblende and pyroxene
NMNH 91322-1572 Andesite
NMNH 91322-1573 Andesite
NMNH 91322-1574 Andesite
NMNH 91322-1575 Andesite with hornblende and mica
NMNH 91322-1576 Andesite with hornblende and mica
NMNH 91322-1577 Andesite with hornblende and mica
NMNH 91322-1578 Granite
NMNH 91322-1579 Andesite with hornblende and mica
NMNH 91322-1580 Andesite with hornblende and mica
NMNH 91322-1581 Andesite with hornblende and mica
NMNH 91322-1582 Andesite with hornblende and mica
NMNH 91322-1583 Andesite with hornblende and mica
NMNH 91322-1584 Andesite with hornblende and mica
NMNH 91322-1585 Andesite with hornblende and mica
NMNH 91322-1586 Andesite with hornblende and mica
NMNH 91322-1587 Andesite with hornblende and mica
NMNH 91322-1588 Andesite with hornblende and mica
NMNH 91322-1589 Andesite with hornblende and mica
NMNH 91322-1590 Andesite with hornblende and mica
NMNH 91322-1591 Andesite with hornblende and mica
NMNH 91322-1592 Andesite
NMNH 91322-1594 Andesite with hornblende and mica
NMNH 91322-1595 Andesite with hornblende and mica
NMNH 91322-1596 Andesite with hornblende and mica
NMNH 91322-1597 Andesite with hornblende and mica
NMNH 91322-1598 Andesite with hornblende and mica
NMNH 91322-1599 Andesite
NMNH 91322-1600 Andesite
NMNH 91322-1601 Andesite
NMNH 91322-1602 Andesite with hornblende and mica
NMNH 91322-1603 Andesite with hornblende and mica
NMNH 91322-1604 Andesite with hornblende and mica
NMNH 91322-1605 Andesite with hornblende and mica
NMNH 91322-1606 Andesite
NMNH 91322-1607 Andesite with hornblende and mica
NMNH 91322-1608 Andesite with hornblende and mica
NMNH 91322-1609 Andesite
NMNH 91322-1610 Andesite
NMNH 91322-1611 Andesite
NMNH 91322-1612 Andesite
NMNH 91322-1613 Andesite
NMNH 91322-1614 Andesite
NMNH 91322-1615 Andesite
NMNH 91322-1616 Andesite
NMNH 91322-1617 Absarokite
NMNH 91322-1618 Absarokite
NMNH 91322-1619 Basalt
NMNH 91322-162 Andesite with hornblende and pyroxene
NMNH 91322-1623 Breccia
NMNH 91322-1624 Absarokite
NMNH 91322-1625 Breccia
NMNH 91322-1626 Breccia
NMNH 91322-1627 Breccia
NMNH 91322-1628 Breccia
NMNH 91322-1629 Breccia
NMNH 91322-1630 Andesite with hornblende and pyroxene
NMNH 91322-1631 Breccia
NMNH 91322-1632 Andesite
NMNH 91322-1633 Andesite
NMNH 91322-1634 Andesite
NMNH 91322-1635 Andesite with hornblende and pyroxene
NMNH 91322-1637 Dacite
NMNH 91322-1638 Basalt
NMNH 91322-1639 Andesite with hornblende and pyroxene
NMNH 91322-164 Andesite with hornblende and mica
NMNH 91322-1641 Andesite with hornblende and pyroxene
NMNH 91322-1642 Andesite with hornblende and pyroxene
NMNH 91322-1643 Banakite
NMNH 91322-1645 Banakite
NMNH 91322-1646 Banakite
NMNH 91322-1647 Shoshonite
NMNH 91322-1648 Shoshonite
NMNH 91322-1649 Shoshonite
NMNH 91322-1650 Rhyolite tuff
NMNH 91322-1651 Shoshonite
NMNH 91322-1652 Andesite
NMNH 91322-1653 Andesite with hornblende and pyroxene
NMNH 91322-1654 Andesite with hornblende and pyroxene
NMNH 91322-1655 Andesite
NMNH 91322-1656 Breccia
NMNH 91322-1657 Andesite
NMNH 91322-1658 Andesite
NMNH 91322-1659 Andesite
NMNH 91322-1660 Andesite with hornblende and pyroxene
NMNH 91322-1661 Andesite with hornblende and mica
NMNH 91322-1662 Andesite
NMNH 91322-1663 Andesite
NMNH 91322-1664 Andesite with hornblende and pyroxene
NMNH 91322-1665 Andesite with hornblende and pyroxene
NMNH 91322-1666 Andesite
NMNH 91322-1667 Andesite with hornblende and pyroxene
NMNH 91322-1668 Basalt
NMNH 91322-1669 Basalt
NMNH 91322-167 Andesite
NMNH 91322-1670 Andesite
NMNH 91322-1671 Basaltic andesite
NMNH 91322-1672 Andesite
NMNH 91322-1673 Andesite
NMNH 91322-1674 Andesite
NMNH 91322-1675 Andesite
NMNH 91322-1676 Basaltic andesite
NMNH 91322-1679 Basaltic andesite
NMNH 91322-168 Dacite
NMNH 91322-1680 Basalt
NMNH 91322-1681 Andesite
NMNH 91322-1682 Andesite
NMNH 91322-1683 Andesite
NMNH 91322-1684 Andesite with hornblende and pyroxene
NMNH 91322-169 Dacite
NMNH 91322-1697 Basalt
NMNH 91322-1698 Absarokite
NMNH 91322-1699 Banakite
NMNH 91322-170 Andesite with hornblende and mica
NMNH 91322-1702 Basalt
NMNH 91322-1703 Basalt
NMNH 91322-1714 Shoshonite
NMNH 91322-1715 Shoshonite
NMNH 91322-1716 Shoshonite
NMNH 91322-1717 Shoshonite
NMNH 91322-1718 Shoshonite
NMNH 91322-1719 Absarokite
NMNH 91322-1720 Absarokite
NMNH 91322-1721 Basalt
NMNH 91322-1722 Basalt with calcite and zeolite
NMNH 91322-1723 Rhyolite tuff
NMNH 91322-1724 Shoshonite
NMNH 91322-1725 Andesite
NMNH 91322-1726 Andesite
NMNH 91322-1727 Andesite
NMNH 91322-1728 Andesite
NMNH 91322-1729 Andesite
NMNH 91322-1730 Andesite
NMNH 91322-1731 Shoshonite
NMNH 91322-1734 Basalt
NMNH 91322-1735 Basalt
NMNH 91322-1736 Andesite with olivine and pyroxene
NMNH 91322-1739 Basalt
NMNH 91322-1743 Absarokite
NMNH 91322-1745 Absarokite
NMNH 91322-1747 Breccia
NMNH 91322-1748 Basalt
NMNH 91322-1749 Basalt
NMNH 91322-1750 Breccia
NMNH 91322-1751 Absarokite
NMNH 91322-1754 Dacite
NMNH 91322-1757 Basalt
NMNH 91322-1758 Basalt
NMNH 91322-1759 Basalt
NMNH 91322-1760 Basalt
NMNH 91322-1761 Basalt
NMNH 91322-1762 Rhyolite
NMNH 91322-1769 Rhyolite
NMNH 91322-1775 Rhyolite
NMNH 91322-1776 Rhyolite
NMNH 91322-1796 Basalt
NMNH 91322-1802 Rhyolite
NMNH 91322-1804 Rhyolite
NMNH 91322-1815 Rhyolite
NMNH 91322-1816 Rhyolite
NMNH 91322-1818 Rhyolite
NMNH 91322-1819 Rhyolite
NMNH 91322-182 Andesite
NMNH 91322-1820 Rhyolite
NMNH 91322-1834 Obsidian
NMNH 91322-1834 Obsidian
NMNH 91322-1835 Obsidian
NMNH 91322-1835 Obsidian
NMNH 91322-1838 Obsidian
NMNH 91322-184 Andesite
NMNH 91322-185 Andesite with hornblende and mica
NMNH 91322-1851 Rhyolite
NMNH 91322-1852 Rhyolite
NMNH 91322-1853 Rhyolite
NMNH 91322-1855 Rhyolite
NMNH 91322-1856 Rhyolite
NMNH 91322-1857 Rhyolite
NMNH 91322-1858 Rhyolite
NMNH 91322-1859 Rhyolite
NMNH 91322-1860 Rhyolite
NMNH 91322-1862 Rhyolite
NMNH 91322-1864 Obsidian
NMNH 91322-1864 Obsidian
NMNH 91322-1865 Obsidian
NMNH 91322-1866 Rhyolitic pumice
NMNH 91322-1867 Rhyolite with hematite and quartz
NMNH 91322-1868 Rhyolite
NMNH 91322-1869 Rhyolite
NMNH 91322-1870 Rhyolite
NMNH 91322-1871 Rhyolite
NMNH 91322-1872 Rhyolite
NMNH 91322-1873 Rhyolite
NMNH 91322-1874 Rhyolite
NMNH 91322-1875 Rhyolite
NMNH 91322-1876 Rhyolite
NMNH 91322-1877 Rhyolite
NMNH 91322-1878 Rhyolite
NMNH 91322-1879 Rhyolite
NMNH 91322-188 Andesite
NMNH 91322-1882 Rhyolite
NMNH 91322-1883 Rhyolite
NMNH 91322-1884 Rhyolite
NMNH 91322-1885 Rhyolite
NMNH 91322-1887 Rhyolite
NMNH 91322-1888 Rhyolite
NMNH 91322-1889 Rhyolite
NMNH 91322-189 Andesite
NMNH 91322-1890 Rhyolite
NMNH 91322-1891 Rhyolite
NMNH 91322-1892 Tuff
NMNH 91322-190 Andesite with hornblende and mica
NMNH 91322-1904 Rhyolite
NMNH 91322-1905 Rhyolite
NMNH 91322-1909 Rhyolite
NMNH 91322-191 Andesite with hornblende and mica
NMNH 91322-1916 Rhyolite
NMNH 91322-1920 Rhyolite
NMNH 91322-1922 Rhyolite
NMNH 91322-1923 Rhyolite
NMNH 91322-1924 Rhyolite
NMNH 91322-1926 Rhyolite
NMNH 91322-1933 Rhyolite
NMNH 91322-1934 Rhyolite
NMNH 91322-1935 Rhyolite
NMNH 91322-1936 Rhyolite
NMNH 91322-1937 Rhyolite
NMNH 91322-1939 Rhyolite
NMNH 91322-1940 Rhyolite
NMNH 91322-1941 Rhyolite
NMNH 91322-1942 Rhyolite
NMNH 91322-1945 Rhyolite
NMNH 91322-1946 Rhyolite
NMNH 91322-1948 Rhyolite
NMNH 91322-1949 Rhyolite
NMNH 91322-195 Andesite
NMNH 91322-1950 Obsidian
NMNH 91322-1950 Rhyolite
NMNH 91322-1951 Obsidian
NMNH 91322-1951 Rhyolite
NMNH 91322-1952 Rhyolite
NMNH 91322-1953 Rhyolite
NMNH 91322-1954 Rhyolite
NMNH 91322-1955 Rhyolite
NMNH 91322-1956 Rhyolite
NMNH 91322-1957 Rhyolite
NMNH 91322-1958 Welded tuff with glass and andesite
NMNH 91322-1959 Rhyolite
NMNH 91322-1960 Rhyolite
NMNH 91322-1961 Rhyolite
NMNH 91322-1964 Rhyolite
NMNH 91322-1966 Rhyolite
NMNH 91322-1967 Rhyolite
NMNH 91322-1968 Obsidian
NMNH 91322-1969 Obsidian
NMNH 91322-197 Andesite with hornblende and mica
NMNH 91322-1971 Rhyolite
NMNH 91322-1972 Rhyolite
NMNH 91322-1973 Rhyolite
NMNH 91322-1976 Obsidian
NMNH 91322-1978 Obsidian
NMNH 91322-1978 Obsidian
NMNH 91322-198 Andesite with hornblende and mica
NMNH 91322-1980 Rhyolite
NMNH 91322-1984 Rhyolite
NMNH 91322-1986 Rhyolite
NMNH 91322-1987 Rhyolite
NMNH 91322-1988 Rhyolite
NMNH 91322-1989 Rhyolite
NMNH 91322-1994 Rhyolite
NMNH 91322-1995 Rhyolite
NMNH 91322-1996 Rhyolite
NMNH 91322-1997 Rhyolite
NMNH 91322-1998 Rhyolite
NMNH 91322-2003 Rhyolite
NMNH 91322-2004 Rhyolite
NMNH 91322-201 Andesite
NMNH 91322-2013 Rhyolitic pumice
NMNH 91322-2014 Rhyolite
NMNH 91322-2015 Rhyolitic pumice
NMNH 91322-2016 Rhyolite
NMNH 91322-2017 Rhyolite
NMNH 91322-2018 Rhyolite
NMNH 91322-2019 Rhyolite
NMNH 91322-2020 Rhyolite
NMNH 91322-2023 Rhyolite
NMNH 91322-2024 Rhyolite
NMNH 91322-2029 Rhyolite
NMNH 91322-2048 Rhyolite
NMNH 91322-2049 Rhyolite
NMNH 91322-2050 Rhyolite
NMNH 91322-2050 Rhyolite
NMNH 91322-2051 Rhyolite
NMNH 91322-2052 Rhyolite
NMNH 91322-2056 Obsidian
NMNH 91322-2056 Obsidian
NMNH 91322-2058 Rhyolitic pumice
NMNH 91322-2059 Rhyolite
NMNH 91322-2060 Rhyolite
NMNH 91322-2061 Rhyolite
NMNH 91322-2062 Rhyolite
NMNH 91322-2063 Rhyolite
NMNH 91322-2064 Rhyolite
NMNH 91322-2066 Obsidian
NMNH 91322-2067 Rhyolite
NMNH 91322-2068 Obsidian
NMNH 91322-2070 Perlite
NMNH 91322-2070 Rhyolite
NMNH 91322-2071 Rhyolite
NMNH 91322-2072 Rhyolite
NMNH 91322-2073 Obsidian
NMNH 91322-2080 Rhyolite
NMNH 91322-2081 Rhyolite
NMNH 91322-2082 Rhyolite sandstone
NMNH 91322-2083 Rhyolitic pumice
NMNH 91322-2084 Rhyolitic pumice
NMNH 91322-2085 Rhyolitic pumice
NMNH 91322-2086 Rhyolite
NMNH 91322-2087 Rhyolite
NMNH 91322-2088 Rhyolite
NMNH 91322-2089 Rhyolite
NMNH 91322-2090 Rhyolite
NMNH 91322-2092 Rhyolite
NMNH 91322-2093 Rhyolite
NMNH 91322-2102 Rhyolite
NMNH 91322-2121 Rhyolite
NMNH 91322-213 Andesite with hornblende and mica
NMNH 91322-2135 Rhyolite
NMNH 91322-2137 Rhyolite
NMNH 91322-2138 Rhyolite
NMNH 91322-214 Andesite with hornblende and mica
NMNH 91322-2141 Rhyolite
NMNH 91322-2142 Rhyolite
NMNH 91322-2143 Rhyolite
NMNH 91322-2145 Rhyolite
NMNH 91322-2146 Rhyolite
NMNH 91322-2147 Rhyolite
NMNH 91322-2148 Rhyolite
NMNH 91322-2149 Rhyolite
NMNH 91322-2155 Rhyolite
NMNH 91322-2157 Rhyolite
NMNH 91322-2158 Rhyolite
NMNH 91322-216 Andesite with hornblende and mica
NMNH 91322-2160 Rhyolite
NMNH 91322-2161 Rhyolite
NMNH 91322-2164 Obsidian
NMNH 91322-2164 Obsidian
NMNH 91322-2166 Rhyolite
NMNH 91322-2167 Rhyolite
NMNH 91322-2168 Obsidian
NMNH 91322-2170 Obsidian
NMNH 91322-2172 Obsidian
NMNH 91322-2174 Obsidian
NMNH 91322-2175 Obsidian
NMNH 91322-2180 Obsidian
NMNH 91322-2184 Obsidian
NMNH 91322-2184 Obsidian
NMNH 91322-2185 Obsidian
NMNH 91322-2186 Obsidian
NMNH 91322-2187 Obsidian
NMNH 91322-2187 Obsidian
NMNH 91322-2187 Obsidian
NMNH 91322-2188 Obsidian
NMNH 91322-2189 Obsidian
NMNH 91322-2189 Obsidian
NMNH 91322-2192 Obsidian
NMNH 91322-2192 Obsidian
NMNH 91322-2193 Obsidian
NMNH 91322-2194 Obsidian
NMNH 91322-2197 Obsidian
NMNH 91322-2198 Obsidian
NMNH 91322-2198 Obsidian
NMNH 91322-2210 Obsidian
NMNH 91322-2215 Obsidian
NMNH 91322-222 Andesite
NMNH 91322-2220 Obsidian
NMNH 91322-2235 Obsidian
NMNH 91322-225 Andesite
NMNH 91322-2253 Rhyolite
NMNH 91322-2254 Obsidian
NMNH 91322-2255 Obsidian
NMNH 91322-2262 Rhyolite
NMNH 91322-2266 Rhyolite
NMNH 91322-2269 Rhyolite
NMNH 91322-2273 Rhyolite
NMNH 91322-2274 Rhyolite
NMNH 91322-2275 Rhyolite
NMNH 91322-2276 Rhyolite
NMNH 91322-2277 Rhyolite
NMNH 91322-2278 Rhyolite
NMNH 91322-2279 Rhyolite
NMNH 91322-228 Andesite with augite and shale
NMNH 91322-2280 Obsidian
NMNH 91322-2282 Igneous rock
NMNH 91322-2283 Obsidian
NMNH 91322-2290 Obsidian
NMNH 91322-2292 Obsidian
NMNH 91322-2294 Igneous rock
NMNH 91322-2295 Obsidian
NMNH 91322-2296 Obsidian
NMNH 91322-2297 Andesite
NMNH 91322-2298 Rhyolite
NMNH 91322-2299 Rhyolite
NMNH 91322-2300 Rhyolite
NMNH 91322-232 Andesite
NMNH 91322-233 Andesite
NMNH 91322-234 Andesite with hornblende and pyroxene
NMNH 91322-235 Andesite with hornblende and pyroxene
NMNH 91322-236 Andesite with hornblende and pyroxene
NMNH 91322-237 Andesite with hornblende and pyroxene
NMNH 91322-238 Andesite
NMNH 91322-239 Andesite
NMNH 91322-240 Andesite
NMNH 91322-241 Andesite
NMNH 91322-242 Andesite
NMNH 91322-243 Andesite
NMNH 91322-244 Andesite
NMNH 91322-245 Andesite
NMNH 91322-246 Andesite with hornblende and mica
NMNH 91322-247 Andesite with hornblende and mica
NMNH 91322-248 Diorite with mica and quartz
NMNH 91322-249 Andesite with hornblende and mica
NMNH 91322-250 Andesite with hornblende and mica
NMNH 91322-251 Andesite with hornblende and mica
NMNH 91322-252 Andesite with hornblende and mica
NMNH 91322-253 Andesite with hornblende and mica
NMNH 91322-254 Andesite with hornblende and mica
NMNH 91322-255 Andesite with hornblende and mica
NMNH 91322-256 Andesite with hornblende and mica
NMNH 91322-257 Andesite with hornblende and mica
NMNH 91322-258 Andesite
NMNH 91322-259 Dacite
NMNH 91322-260 Dacite
NMNH 91322-261 Dacite
NMNH 91322-262 Dacite
NMNH 91322-263 Dacite
NMNH 91322-264 Dacite
NMNH 91322-265 Dacite
NMNH 91322-266 Diorite with mica and pyroxene
NMNH 91322-267 Diorite
NMNH 91322-268 Diorite with mica and pyroxene
NMNH 91322-269 Diorite with mica and pyroxene
NMNH 91322-270 Diorite with mica and pyroxene
NMNH 91322-271 Diorite with mica and pyroxene
NMNH 91322-272 Diorite
NMNH 91322-273 Diorite
NMNH 91322-274 Diorite
NMNH 91322-275 Diorite with mica and quartz
NMNH 91322-276 Diorite with mica and pyroxene
NMNH 91322-277 Diorite with mica and pyroxene
NMNH 91322-278 Diorite with mica and pyroxene
NMNH 91322-279 Diorite with mica and pyroxene
NMNH 91322-280 Diorite with mica and pyroxene
NMNH 91322-281 Diorite with mica and pyroxene
NMNH 91322-282 Diorite with mica and pyroxene
NMNH 91322-283 Diorite with mica and pyroxene
NMNH 91322-284 Diorite with mica and pyroxene
NMNH 91322-285 Diorite with mica and pyroxene
NMNH 91322-286 Diorite with mica and pyroxene
NMNH 91322-288 Diorite with mica and pyroxene
NMNH 91322-289 Diorite with mica and pyroxene
NMNH 91322-290 Diorite with mica and pyroxene
NMNH 91322-291 "Diorite with mica, pyroxene, and others"
NMNH 91322-294 Diorite
NMNH 91322-295 Diorite with mica and pyroxene
NMNH 91322-296 Diorite with mica and pyroxene
NMNH 91322-297 Diorite
NMNH 91322-298 Diorite with mica and pyroxene
NMNH 91322-299 Diorite with mica and pyroxene
NMNH 91322-300 Diorite with mica and pyroxene
NMNH 91322-301 Diorite with mica and quartz
NMNH 91322-302 Diorite with mica and quartz
NMNH 91322-303 Diorite with mica and quartz
NMNH 91322-304 Diorite with mica and quartz
NMNH 91322-305 Diorite with mica and quartz
NMNH 91322-306 Diorite with mica and quartz
NMNH 91322-307 Diorite with mica and quartz
NMNH 91322-308 Sandstone
NMNH 91322-3089 Igneous rock
NMNH 91322-309 Diorite with mica and quartz
NMNH 91322-310 Diorite with mica and quartz
NMNH 91322-3101 Gneiss
NMNH 91322-3102 Quartzite
NMNH 91322-3103 Quartzite
NMNH 91322-3104 Sandstone
NMNH 91322-3106 Limestone
NMNH 91322-3107 Limestone
NMNH 91322-3108 Limestone
NMNH 91322-3109 Limestone
NMNH 91322-311 Diorite with mica and quartz
NMNH 91322-3110 Limestone
NMNH 91322-3111 Limestone
NMNH 91322-3112 Limestone
NMNH 91322-3113 Limestone
NMNH 91322-3114 Ferruginous limestone
NMNH 91322-3115 Ferruginous limestone
NMNH 91322-3116 Shale
NMNH 91322-3117 Limestone
NMNH 91322-3118 Limestone
NMNH 91322-3119 Limestone
NMNH 91322-312 Diorite with mica and quartz
NMNH 91322-3120 Limestone
NMNH 91322-3121 Limestone
NMNH 91322-3122 Limestone
NMNH 91322-3123 Shale
NMNH 91322-3124 Limestone
NMNH 91322-3125 Shale
NMNH 91322-3126 Limestone
NMNH 91322-3127 Limestone
NMNH 91322-3128 Limestone
NMNH 91322-3129 Limestone
NMNH 91322-313 Diorite with mica and quartz
NMNH 91322-3130 Limestone
NMNH 91322-3131 Limestone with calcite and iron oxide
NMNH 91322-3132 Limestone
NMNH 91322-3133 Limestone
NMNH 91322-3134 Limestone
NMNH 91322-3135 Limestone
NMNH 91322-3136 Limestone
NMNH 91322-3137 Limestone
NMNH 91322-3138 Cherty limestone
NMNH 91322-3139 Cherty limestone
NMNH 91322-314 Diorite with mica and quartz
NMNH 91322-3140 Cherty limestone
NMNH 91322-3141 Limestone
NMNH 91322-3142 Argillaceous limestone
NMNH 91322-3143 Fossilferous limestone
NMNH 91322-3144 Argillaceous limestone
NMNH 91322-3145 Limestone
NMNH 91322-3146 Limestone
NMNH 91322-3147 Limestone
NMNH 91322-3148 Limestone
NMNH 91322-3149 Limestone
NMNH 91322-315 Diorite with mica and quartz
NMNH 91322-3150 Limestone
NMNH 91322-3151 Limestone
NMNH 91322-3152 Limestone
NMNH 91322-3153 Limestone
NMNH 91322-3154 Quartzite
NMNH 91322-3155 Quartzite
NMNH 91322-3156 Quartzite
NMNH 91322-3157 Slate
NMNH 91322-3158 Limestone
NMNH 91322-3159 Limestone
NMNH 91322-316 Diorite with mica and quartz
NMNH 91322-3160 Limestone
NMNH 91322-3161 Unidentified
NMNH 91322-3162 Limestone
NMNH 91322-3163 Limestone
NMNH 91322-3164 Shale
NMNH 91322-3165 Shale
NMNH 91322-3166 Shale
NMNH 91322-3167 Limestone
NMNH 91322-3168 Limestone
NMNH 91322-3169 Sandstone
NMNH 91322-317 Diorite with mica and quartz
NMNH 91322-3170 Limestone
NMNH 91322-3171 Oolitic limestone
NMNH 91322-3172 Sandstone
NMNH 91322-3173 Limestone
NMNH 91322-3174 Limestone
NMNH 91322-3175 Quartzite
NMNH 91322-3176 Quartzite
NMNH 91322-3177 Limestone
NMNH 91322-3178 Sandstone
NMNH 91322-3179 Calcareous sandstone
NMNH 91322-318 Diorite with mica and quartz
NMNH 91322-3180 Arenaceous limestone
NMNH 91322-3181 Shale
NMNH 91322-3182 Limestone
NMNH 91322-3183 Sandstone
NMNH 91322-3184 Calcareous sandstone
NMNH 91322-3185 Calcareous sandstone
NMNH 91322-3186 Calcareous sandstone
NMNH 91322-3187 Conglomerate
NMNH 91322-3188 Sandstone
NMNH 91322-3189 Sandstone
NMNH 91322-319 Diorite with mica and quartz
NMNH 91322-3190 Sandstone
NMNH 91322-3191 Arenaceous limestone
NMNH 91322-3192 Argillaceous sandstone
NMNH 91322-3193 Calcareous sandstone
NMNH 91322-3194 Sandstone
NMNH 91322-3195 Argillaceous sandstone
NMNH 91322-3196 Carbonaceous sandstone
NMNH 91322-3197 Ferruginous sandstone
NMNH 91322-3198 Carbonaceous shale
NMNH 91322-3199 Siliceous shale
NMNH 91322-320 Diorite with mica and quartz
NMNH 91322-3200 Ferruginous shale
NMNH 91322-3201 Siliceous shale
NMNH 91322-3202 Siliceous shale
NMNH 91322-3203 Siliceous shale
NMNH 91322-3204 Siliceous shale
NMNH 91322-3205 Quartzite
NMNH 91322-3206 Quartzite
NMNH 91322-321 Diorite with mica and quartz
NMNH 91322-322 Diorite with mica and quartz
NMNH 91322-323 Diorite with mica and quartz
NMNH 91322-326 Diorite with mica and quartz
NMNH 91322-3260 Igneous rock
NMNH 91322-328 Diorite with mica and quartz
NMNH 91322-329 Diorite with mica and quartz
NMNH 91322-330 Diorite with mica and quartz
NMNH 91322-331 Diorite with mica and quartz
NMNH 91322-332 Diorite with mica and quartz
NMNH 91322-333 Diorite with mica and quartz
NMNH 91322-334 Diorite with mica and quartz
NMNH 91322-3357 Clay concretion
NMNH 91322-3453 Diorite
NMNH 91322-356 Andesite with feldspar and pyroxene
NMNH 91322-357 Andesite with feldspar and pyroxene
NMNH 91322-359 Andesite
NMNH 91322-360 Andesite
NMNH 91322-361 Andesite
NMNH 91322-362 Andesite
NMNH 91322-363 Andesite
NMNH 91322-365 Andesite
NMNH 91322-3698 Diorite
NMNH 91322-3699 Andesite with hornblende and pyroxene
NMNH 91322-3700 Basalt
NMNH 91322-3701 Absarokite
NMNH 91322-3702 Basalt
NMNH 91322-3703 Basalt
NMNH 91322-3704 Mud
NMNH 91322-3705 Diorite
NMNH 91322-3706 Andesite with hornblende and pyroxene
NMNH 91322-3707 Absarokite
NMNH 91322-3708 Andesite with hornblende and pyroxene
NMNH 91322-3709 Basalt
NMNH 91322-3710 "Absarokite with augite, hornblende, and others"
NMNH 91322-3711 Absarokite
NMNH 91322-3712 Andesite with mica and basalt
NMNH 91322-3713 Diorite
NMNH 91322-3714 Absarokite
NMNH 91322-3715 Absarokite
NMNH 91322-3716 Shoshonite
NMNH 91322-3717 Basalt
NMNH 91322-3718 Absarokite
NMNH 91322-3719 Diorite with mica and breccia
NMNH 91322-3720 Feldspar
NMNH 91322-3721 Banakite
NMNH 91322-3722 Basalt
NMNH 91322-3723 Banakite
NMNH 91322-3724 Banakite
NMNH 91322-3725 Absarokite
NMNH 91322-3726 Basalt
NMNH 91322-3727 Dyke rock
NMNH 91322-3728 Dyke rock
NMNH 91322-3729 Dyke rock
NMNH 91322-3730 Banakite
NMNH 91322-3731 Basalt
NMNH 91322-3732 Breccia
NMNH 91322-3733 Syenite
NMNH 91322-3734 Syenite
NMNH 91322-3735 Basalt
NMNH 91322-3736 Absarokite
NMNH 91322-3737 Syenite
NMNH 91322-3738 Syenite
NMNH 91322-3739 Syenite
NMNH 91322-3740 Breccia
NMNH 91322-3741 Syenite with augite and quartz
NMNH 91322-3742 Syenite
NMNH 91322-3743 Syenite
NMNH 91322-3744 Syenite
NMNH 91322-3745 Breccia
NMNH 91322-3746 Syenite with augite and biotite
NMNH 91322-379 Basalt
NMNH 91322-381 Absarokite
NMNH 91322-385 Andesite
NMNH 91322-386 Andesite
NMNH 91322-387 Andesite
NMNH 91322-388 Andesite
NMNH 91322-390 Andesite
NMNH 91322-391 Andesite
NMNH 91322-392 Andesite
NMNH 91322-393 Andesite
NMNH 91322-394 Andesite
NMNH 91322-395 Andesite
NMNH 91322-396 Andesite
NMNH 91322-397 Andesite
NMNH 91322-398 Andesite
NMNH 91322-399 Unidentified
NMNH 91322-400 Andesite
NMNH 91322-401 Andesite with hornblende and pyroxene
NMNH 91322-402 Andesite with hornblende and pyroxene
NMNH 91322-403 Basalt
NMNH 91322-404 Andesite with hornblende and pyroxene
NMNH 91322-405 Andesite with hornblende and pyroxene
NMNH 91322-406 Andesite with hornblende and pyroxene
NMNH 91322-407 Andesite with hornblende and pyroxene
NMNH 91322-409 Andesite with hornblende and pyroxene
NMNH 91322-410 Andesite with hornblende and pyroxene
NMNH 91322-411 Andesite with hornblende and pyroxene
NMNH 91322-412 Andesite with hornblende and pyroxene
NMNH 91322-413 Andesite with hornblende and pyroxene
NMNH 91322-414 Andesite with hornblende and pyroxene
NMNH 91322-415 Andesite with hornblende and pyroxene
NMNH 91322-416 Andesite with hornblende and pyroxene
NMNH 91322-417 Basalt
NMNH 91322-418 Andesite with hornblende and pyroxene
NMNH 91322-419 Andesite with hornblende and pyroxene
NMNH 91322-420 Andesite with hornblende and pyroxene
NMNH 91322-421 Andesite
NMNH 91322-422 Andesite
NMNH 91322-423 Andesite
NMNH 91322-424 Andesite
NMNH 91322-425 Andesite
NMNH 91322-426 Andesite
NMNH 91322-427 Andesite
NMNH 91322-428 Andesite
NMNH 91322-429 Andesite
NMNH 91322-430 Andesite
NMNH 91322-431 Andesite with hornblende and pyroxene
NMNH 91322-432 Andesite with hornblende and pyroxene
NMNH 91322-433 Andesite with hornblende and pyroxene
NMNH 91322-434 Andesite with hornblende and pyroxene
NMNH 91322-436 Andesite with hornblende and pyroxene
NMNH 91322-437 Andesite with hornblende and pyroxene
NMNH 91322-439 Andesite with hornblende and pyroxene
NMNH 91322-440 Andesite with hornblende and pyroxene
NMNH 91322-441 Andesite with hornblende and pyroxene
NMNH 91322-442 Andesite with hornblende and pyroxene
NMNH 91322-443 Andesite
NMNH 91322-445 Andesite
NMNH 91322-446 Andesite
NMNH 91322-447 Andesite
NMNH 91322-448 Andesite
NMNH 91322-449 Andesite
NMNH 91322-450 Andesite
NMNH 91322-451 Andesite
NMNH 91322-452 Andesite
NMNH 91322-453 Andesite
NMNH 91322-454 Andesite
NMNH 91322-455 Andesite
NMNH 91322-456 Andesite
NMNH 91322-457 Andesite
NMNH 91322-458 Andesite
NMNH 91322-459 Andesite
NMNH 91322-460 Andesite
NMNH 91322-461 Andesite
NMNH 91322-462 Andesite
NMNH 91322-463 Andesite
NMNH 91322-464 Andesite
NMNH 91322-465 Andesite
NMNH 91322-466 Andesite
NMNH 91322-467 Andesite
NMNH 91322-468 Andesite
NMNH 91322-469 Andesite
NMNH 91322-470 Andesite
NMNH 91322-471 Andesite
NMNH 91322-472 Andesite
NMNH 91322-473 Andesite
NMNH 91322-474 Andesite
NMNH 91322-475 Andesite
NMNH 91322-476 Andesite with hornblende and mica
NMNH 91322-477 Andesite
NMNH 91322-478 Andesite
NMNH 91322-479 Andesite
NMNH 91322-480 Andesite with hornblende and pyroxene
NMNH 91322-481 Andesite with hornblende and mica
NMNH 91322-482 Andesite with hornblende and mica
NMNH 91322-484 Andesite with hornblende and mica
NMNH 91322-485 Andesite with hornblende and mica
NMNH 91322-486 Andesite with hornblende and mica
NMNH 91322-487 Andesite with hornblende and mica
NMNH 91322-488 Andesite with hornblende and mica
NMNH 91322-489 Andesite with hornblende and mica
NMNH 91322-490 Andesite with hornblende and mica
NMNH 91322-491 Andesite with hornblende and mica
NMNH 91322-492 Andesite with hornblende and mica
NMNH 91322-493 Andesite with hornblende and mica
NMNH 91322-494 Andesite with hornblende and mica
NMNH 91322-495 Andesite with hornblende and mica
NMNH 91322-496 Andesite with hornblende and mica
NMNH 91322-497 Andesite with hornblende and mica
NMNH 91322-498 Dacite
NMNH 91322-499 Dacite
NMNH 91322-500 Dacite
NMNH 91322-5000 Perlite
NMNH 91322-5001 Rhyolite
NMNH 91322-5002 Rhyolite
NMNH 91322-5003 Unidentified
NMNH 91322-5004 Unidentified
NMNH 91322-5005 Unidentified
NMNH 91322-5006 Unidentified
NMNH 91322-5007 Unidentified
NMNH 91322-5008 Rhyolite
NMNH 91322-5009 Unidentified
NMNH 91322-501 Dacite
NMNH 91322-5010 Unidentified
NMNH 91322-5011 Perlite
NMNH 91322-5012 Unidentified
NMNH 91322-5013 Unidentified
NMNH 91322-5014 Rhyolite
NMNH 91322-5015 Rhyolite
NMNH 91322-5016 Unidentified
NMNH 91322-5017 Rhyolite
NMNH 91322-5018 Unidentified
NMNH 91322-5019 Rhyolite
NMNH 91322-502 Dacite
NMNH 91322-5020 Rhyolite
NMNH 91322-5021 Unidentified
NMNH 91322-5022 Unidentified
NMNH 91322-5023 Unidentified
NMNH 91322-5024 Unidentified
NMNH 91322-5025 Andesite
NMNH 91322-5026 Dyke rock
NMNH 91322-5027 Dyke rock
NMNH 91322-5028 Unidentified
NMNH 91322-5029 Unidentified
NMNH 91322-503 Dacite
NMNH 91322-5030 Unidentified
NMNH 91322-5031 Andesite
NMNH 91322-5032 Unidentified
NMNH 91322-5033 Unidentified
NMNH 91322-5034 Unidentified
NMNH 91322-5035 Unidentified
NMNH 91322-5036 Unidentified
NMNH 91322-5037 Unidentified
NMNH 91322-5038 Unidentified
NMNH 91322-5039 Andesite
NMNH 91322-504 Dacite
NMNH 91322-5040 Unidentified
NMNH 91322-5041 Unidentified
NMNH 91322-5042 Unidentified
NMNH 91322-5043 Unidentified
NMNH 91322-5044 Unidentified
NMNH 91322-5045 Unidentified
NMNH 91322-5046 Unidentified
NMNH 91322-5047 Rhyolite
NMNH 91322-5048 Unidentified
NMNH 91322-5049 Basalt
NMNH 91322-505 Dacite
NMNH 91322-5050 Rhyolite
NMNH 91322-5051 Obsidian
NMNH 91322-5052 Unidentified
NMNH 91322-5053 Unidentified
NMNH 91322-5054 Sandstone
NMNH 91322-5055 Unidentified
NMNH 91322-5056 Rhyolite
NMNH 91322-5057 Unidentified
NMNH 91322-5058 Basalt
NMNH 91322-5059 Basalt
NMNH 91322-506 Dacite
NMNH 91322-5060 Basalt
NMNH 91322-5061 Unidentified
NMNH 91322-5062 Unidentified
NMNH 91322-5063 Unidentified
NMNH 91322-5064 Unidentified
NMNH 91322-5065 Unidentified
NMNH 91322-5066 Unidentified
NMNH 91322-5067 Unidentified
NMNH 91322-5068 Unidentified
NMNH 91322-5069 Unidentified
NMNH 91322-507 Dacite
NMNH 91322-5070 Unidentified
NMNH 91322-5071 Unidentified
NMNH 91322-5072 Unidentified
NMNH 91322-5073 Andesite
NMNH 91322-5074 Unidentified
NMNH 91322-5075 Dyke rock
NMNH 91322-5076 Unidentified
NMNH 91322-5077 Unidentified
NMNH 91322-5078 Dyke rock
NMNH 91322-5079 Unidentified
NMNH 91322-508 Dacite
NMNH 91322-5080 Unidentified
NMNH 91322-5081 Unidentified
NMNH 91322-5082 Unidentified
NMNH 91322-5083 Unidentified
NMNH 91322-5084 Rhyolite
NMNH 91322-5085 Rhyolite
NMNH 91322-5086 Rhyolite
NMNH 91322-5087 Unidentified
NMNH 91322-5088 Unidentified
NMNH 91322-5089 Unidentified
NMNH 91322-509 Dacite
NMNH 91322-5090 Perlite
NMNH 91322-5091 Rhyolite
NMNH 91322-5092 Unidentified
NMNH 91322-5093 Unidentified
NMNH 91322-5094 Unidentified
NMNH 91322-5095 Rhyolite
NMNH 91322-5096 Rhyolite
NMNH 91322-5097 Unidentified
NMNH 91322-51 Breccia
NMNH 91322-510 Dacite
NMNH 91322-511 Dacite
NMNH 91322-512 Dacite
NMNH 91322-513 Dacite
NMNH 91322-514 Dacite
NMNH 91322-515 Dacite
NMNH 91322-516 Dacite
NMNH 91322-517 Dacite
NMNH 91322-518 Dacite
NMNH 91322-519 Dacite
NMNH 91322-520 Dacite
NMNH 91322-521 Dacite
NMNH 91322-522 Dacite
NMNH 91322-523 Dacite
NMNH 91322-524 Dacite
NMNH 91322-525 Dacite
NMNH 91322-526 Dacite
NMNH 91322-527 Dacite
NMNH 91322-543 Andesite with hornblende and mica
NMNH 91322-55 Andesite with hornblende and mica
NMNH 91322-56 Andesite with hornblende and mica
NMNH 91322-57 Andesite with hornblende and mica
NMNH 91322-578 Shoshonite
NMNH 91322-579 Shoshonite
NMNH 91322-580 Shoshonite
NMNH 91322-582 Basalt
NMNH 91322-584 Basalt
NMNH 91322-586 Basalt
NMNH 91322-587 Basalt
NMNH 91322-588 Basalt
NMNH 91322-589 Basalt
NMNH 91322-591 Basalt
NMNH 91322-593 Basalt
NMNH 91322-594 Basalt
NMNH 91322-596 Basalt
NMNH 91322-597 Basalt
NMNH 91322-598 Basalt
NMNH 91322-599 Basalt
NMNH 91322-60 Andesite with hornblende and mica
NMNH 91322-602 Basalt
NMNH 91322-603 Basalt
NMNH 91322-605 Basalt
NMNH 91322-606 Basalt
NMNH 91322-607 Basalt
NMNH 91322-609 Basalt
NMNH 91322-61 Andesite with hornblende and mica
NMNH 91322-610 Basalt
NMNH 91322-611 Basalt
NMNH 91322-612 Basalt
NMNH 91322-613 Basalt
NMNH 91322-614 Basalt
NMNH 91322-615 Basalt
NMNH 91322-616 Basalt
NMNH 91322-618 Basalt
NMNH 91322-619 Basalt
NMNH 91322-62 Andesite with hornblende and mica
NMNH 91322-620 Basalt
NMNH 91322-621 Basalt
NMNH 91322-622 Basalt
NMNH 91322-623 Basalt
NMNH 91322-624 Basalt
NMNH 91322-625 Basalt
NMNH 91322-626 Basalt
NMNH 91322-627 Basalt
NMNH 91322-63 Andesite with hornblende and mica
NMNH 91322-632 Basalt
NMNH 91322-634 Basalt
NMNH 91322-636 Basalt
NMNH 91322-637 Basalt
NMNH 91322-638 Basalt
NMNH 91322-639 Basalt
NMNH 91322-652 Basalt
NMNH 91322-653 Basalt
NMNH 91322-654 Basalt
NMNH 91322-655 Basalt
NMNH 91322-658 Basalt
NMNH 91322-66 Andesite with hornblende and mica
NMNH 91322-660 Basalt
NMNH 91322-661 Basalt
NMNH 91322-662 Basalt
NMNH 91322-663 Basalt
NMNH 91322-666 Basalt
NMNH 91322-67 Limestone
NMNH 91322-670 Rhyolite
NMNH 91322-671 Basalt
NMNH 91322-679 Trachytic rhyolite
NMNH 91322-68 Andesite with hornblende and mica
NMNH 91322-683 Trachytic rhyolite
NMNH 91322-684 Trachytic rhyolite
NMNH 91322-69 Andesite with hornblende and mica
NMNH 91322-70 Andesite with hornblende and mica
NMNH 91322-71 "Andesite with hornblende, mica, and others"
NMNH 91322-72 Andesite with hornblende and mica
NMNH 91322-73 Andesite with hornblende and mica
NMNH 91322-732 Andesite
NMNH 91322-76 Andesite with hornblende and mica
NMNH 91322-77 Dacite
NMNH 91322-80 Dacite
NMNH 91322-81 Dacite
NMNH 91322-82 Dacite
NMNH 91322-83 Dacite
NMNH 91322-84 Dacite
NMNH 91322-86 Dacite
NMNH 91322-87 Dacite
NMNH 91322-88 Dacite
NMNH 91322-90 Dacite
NMNH 91322-93 Dacite
NMNH 91322-94 Dacite
NMNH 91322-95 Dacite
NMNH 91322-96 Dacite
NMNH 91322-97 Dacite
NMNH 91322-98 Dacite
NMNH 91322-981 Basalt
NMNH 95680 Obsidian

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