Arches National Park
Utah park containing hundreds of sandstone arches eroded from the Jurassic Entrada Formation.
The Colorado River carved this canyon in Paleozoic and Precambrian rocks in Northern Arizona.
Brightly colored hoodoos carved from Tertiary lake sediment of the Carmel Fromation characterize this park.
Mesa Verde National Park
In the Colorado Park ancient Puebloan Indian built kivas and houses in natural alcoves in Cretaceous Sandstone.
Zion National Park
Utah park where tributaries of the Virgin River have carved canyons in the Navajo Sandstone.
Utah park underlain by the Waterpocket monocline where the Navajo sandstone eroded into dome-shaped monoliths.
Yellowstone National Park
Here geysers, mudpots, and thermal springs lie on top of a "supervolcano."
Mount Rainier National Park
This 14,411 ft (4,392 m) stratovolcano in Washington state is the highest mountain in the Cascade Range.
Crater Lake National Park
This large lake in Oregon occupies a caldera created when the 12,000 foot (3,660 meter) high stratovolcano, Mount Mazama, catastrophically erupted 7,700 years ago.
Rocky Mountain National Park
Longs Peak, composed of Precambrian granite, lies in this Colorado Park.
Painted Desert National Park
The northern extension of Petrified Forest underlain by the colorful Chinlee Formation.
Petrified Forest National Park
Arizona park underlain by the Triassic Chinlee Formation containing the petrified remains of a tropical forest.
Lassen Peak National Park
Felsic lava dome in California that is the southernmost Cascade volcano. Last erupted in 1917.
Craters of the Moon National Monument
Holocene basalt flows and cinder cones in Idaho's Snake River Plain
Glacier National Park
National Park in Montana containing glaciated mountains composed of Precambrian sedimentary rocks.
Canyonlands National Park
Utah park at the confluence of the Green and Colorado Rivers containing canyons, arches, and grabens in Paleozoic - Mesozoic sedimentary rock.
North Cascade National Park
The Washington park is composed of rocky terranes recently accreted to North America (geologicallly speaking).