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).

This image is made available under the Public Domain Dedication CC0 license, but proper attribution is appreciated.

Yellowstone