The Yellowstone Plateau-Island Park Region

Route

Start point

Jackson Hole, Wyoming

End point

Ashton, Idaho

Roads

U.S. 89/287/191, roads through Yellowstone National Park

Total distance

152.8 miles

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Geology

Summary

The Yellowstone Plateau, at the center of one of the Earth's largest volcanic fields, spans the continental divide between the Northern and Middle Rocky Mountains at an average elevation of about 2,400 m. The eruptions of the Yellowstone Plateau volcanic field, entirely postdating 2.5 Ma, were exceedingly voluminous but are only the surficial expression of the emplacement of a batholithic volume of rhyolitic magma to high crustal levels. Although the latest eruptions were about 70,000 years ago, an immense hydrothermal system and a variety of geophysical characteristics indicate the continued presence of an active shallow magma chamber.

Key Lithologic Features

• volcanic tuffs, including:
  • Lava Creek Tuff
  • Huckelberry Ridge Tuff
  • Mesa Falls Tuff
• rhyolitic lava flows of the Yellowstone Plateau volcanic field
• basalts of the Yellowstone Plateau volcanic field
• glacial deposits of the Pinedale glaciation
• Mt. Washburn volcanics (Eocene Absaroka volcanic field)
• travertine terrances at Mammoth Hot Springs
• mixed rhyolite and basalts of the Gardner River
• Island Park rhyolite

Structures

• Yellowstone caldera
• Hebgen Fault
• Centennial Fault
• Henry's Fork Caldera
• Big Bend Ridge Caldera

Landforms

• Teton Range
• Pitchstone Plateau
• Lewis River Canyon
• Yellowstone caldera
• Grand Canyon of the Yellowstone
• Tower Falls and the Narrows of the Grand Canyon of the Yellowstone
• Mammoth Hot Springs
• Gallatin Range
• Gibbon Falls
• Yellowstone Plateau
• Hebgen Fault scarp
• Madison Range
• Centennial Range
• Lower Mesa Falls
• Snake River Butte

Other Features

• West Thumb Geyser Basin and hydrotherrmal features (boardwalk loop)
• Mud Volcano hydrothermal area
• Mammoth Hot Springs
• Norris Geyser Basin
• Pocket Basin hydrothermal explosion crater
• hydrothermal features of the Fountain Group
• Midway Geyser Basin
• Upper Geyser Basin
• Quake Lake (earthquake landslide)

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Reference

Christiansen, R.L., 1989, The Yellowstone Plateau-Island Park Region, in Ruebelmann, K.L., ed., Snake River Plain-Yellowstone Volcanic Province : 28th International Geological Congress, Field Trip Guidebook T305: Washington, D.C., American Geophysical Union, p.14-37.

Availability

Order from the American Geophysical Union Bookstore. Go to the AGU On Line Book Catalog for ordering information.