Global Volcanism Program | Image GVP-03153
The Lava Cast Forest lava flow on the NW flank of Newberry formed about 7,000 years ago. It contains hollow tree molds that stand above the surface of the flow. These features formed when flowing lava chilled around standing tree trunks that subsequently burned from the heat of the lava. Horizontal tree molds formed around trees that had either previously fallen or were toppled by the advancing lava flow.
Photo by Lee Siebert, 1972 (Smithsonian Institution).
This image is made available under the Public Domain Dedication CC0 license, but proper attribution is appreciated.