The Absaroka volcanoes were active 53 to 43 million years ago, after the uplift of the Rocky Mountains but before the geologically recent arrival of the Yellowstone hotspot about 2 million years ago.

ends in the remote Absaroka Range. Our only human neighbors were ...

The geology of the eastern portion of Yellowstone National Park, outside the boundaries on Yellowstone Caldera, is dominated by the Absarokas—a volcanic range that was active from about 53 to 43 ...