An aerial view from the NW shows North Sister (center) and Middle Sister (right) with young lava flows from N-flank scoria cones. The latest dated lava flow originated about 1,600 years ago from Collier Cone, near the center of the photo below the left flank of North Sister. One lava flow lobe traveled to the NW and levees on the western lobe are visible in the right foreground. They western lobe traveled 13.5 km down the White Branch Creek valley.

Photo by Dan Miller, 1977 (U.S. Geological Survey).

This image is made available as a Public Domain Work, but proper attribution is appreciated.

Keywords: stratovolcano | lava flow | levee | lava lobe

Three Sisters