Geology and Evolution of the Grand Canyon of the Yellowstone, Yellowstone National Park, Wyoming

Click for route map


Start point

Inspiration Point, Yellowstone National Park

End point

Chittenden Bridge, Yellowstone National Park

Roads (and Trails)

paved roads within Yellowstone National Park, North Rim Trail, South Rim Trail, Lookout Trail

Total distance

not given



This field guide concerns that part of the Grand Canyon of the Yellowstone seen by most visitors between Chittenden Bridge and Sevenmile Hole. The focus of the field guide is the stratigraphy and erosional history of the volcanic and sedimentary rocks (all younger than 610 Ka) that are observed in the canyon walls at 11 locations within or adjacent to the canyon: Inspiration Point, Red Rock, Lower and Upper Falls, Cascade Creek, Uncle Toms Trail, Uncle Toms Rest Area, Artist Point, and a location near Chittenden Bridge. The volcanic and sedimentary features observed at the various stops are discussed in terms of a sequential geologic framework.

Key Lithologic Features

  • rhyolite flows (e.g., Canyon Rhyolite and Hayden Valley flow), some displaying heavy hydrothermal alteration
  • rhyolitic pyroclastics (e.g., Tuff of Uncle Toms Trail and unnamed pumices)
  • Pleistocene sediments (mostly alluvial, shallow lacustrine, and glacial in origin)


  • erosional unconformities


  • Grand Canyon of the Yellowstone

Other Features


Richmond, G.M., 1987, Geology and evolution of the Grand Canyon of the Yellowstone, Yellowstone National Park, Wyoming, in Beus, S.S., ed., Centennial Field Guide Volume 2: Rocky Mountain Section of the Geological Society of America , p. 155-160.


Out of print. Check Digital access to this publication is available via the links in the references section above.