Grand Canyon of the Yellowstone.
20th c American Topographical View

Oliver SEELY Jr. (1939 - ) Primary
1982
20th c
Canyon
Yellowstone National Park. Wyoming. U.S.A.
osus0198
This vallery is a classic example of a V-shaped valley cut by rapid downcutting by the river. The underlying volcanic rock, (tuff) is relatively soft and the cutting action was very rapid.