Rock Springs in Sweetwater County, Wyoming — The American West (Mountains)

Art Gallery of Time

Photographed by Jimmy Emerson

1. Art Gallery of Time Marker

Inscription.
Major John Wesley Powell named the Flaming Gorge and tributaries such as Little Firehole Canyon for the brilliant red sandstones exposed in the canyon walls. Embarking from what is now Green River, Wyoming in specially designed river dory boats, Powell completed two voyages down the Green and Colorado rivers through the Grand Canyon. The first, in 1869, was largely exploratory. The second, in 1871, collected scientific data and produced the first maps of the upper Colorado drainage system. Powell's work formed the basis for much of what geologists now know about the region.

The Green River through Flaming Gorge is a classic example of a superposed stream - it flows across the eastern end of the Uinta Mountains, rather than draining away from the mountains. Geologists believe that, when the last major regional erosion cycle began several million years ago, an extensive landscape nearly level with the present crest of the Uintas dominated southern Wyoming. As erosion removed softer rock the river level was gradually lowered, cutting a precipitous canyon into the resistant core of the Uintas. The result is the spectacular

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Red Canyon of the Green River, which chronicles earth history. Rocks in the very near area are young, only about 49 million years old. Traveling down tributary canyons, such as Little Firehole, and continuing downstream towards Flaming Gorge Dam, older rock formations contain a wide variety of fossils, ranging from dinosaurs to primitive sea life. Near Flaming Gorge Dam, the dark red sandstones and shales of the pre-Cambrian Uinta core form the near vertical canyon walls. These rocks are nearly 1.1 billion years old.

Topics. This historical marker is listed in these topic lists: Exploration • Waterways & Vessels. A significant historical year for this entry is 1869.

Location. 41° 24.253′ N, 109° 18.432′ W. Marker is in Rock Springs, Wyoming, in Sweetwater County. It is on US Hwy 191 (U.S. 191), on the left when traveling south. Touch for map. Marker is in this post office area: Rock Springs WY 82901, United States of America. Touch for directions.

Regionally, this marker is in the Westward Expansion Trails Region.

It is also in the American Mountain West.

Globally, it is in North America,

the Rocky Mountains,

the Western

Flaming Gorge image. Click for full size.

E.O. Beamon, J.W. Powell, A.H. Thompson (courtesy of the New York Public Library), 1871

2. Flaming Gorge

Stereograph of the Flaming Gorge made by the 1871 Powell Expedition (mentioned on marker)

Hemisphere,

the Western World,

and the Anglosphere.

Historically, it finds itself in what was once Mexico’s Alta California.

Other nearby markers. At least 8 other markers are within 12 miles of this marker, measured as the crow flies: Sodium Carbonate Brine (approx. 11.4 miles away); The Overland Stage (approx. 11½ miles away); The Overland Stage Station Route (approx. 11½ miles away); Green River City Hall - 1942-1954 (approx. 11.8 miles away); Riverside Swimming Pool (approx. 11.8 miles away); Norm Nevills & A.K. Reynolds - 1940's (approx. 11.8 miles away); The French Trio - 1938 (approx. 11.8 miles away); William Ashley - 1825 (approx. 11.8 miles away).

Credits. This page was last revised on October 23, 2025. It was originally submitted on October 12, 2025, by Jimmy Emerson of Dalton, Georgia. This page has been viewed 59 times since then and 25 times this year. Photos: 1. submitted on October 12, 2025, by Jimmy Emerson of Dalton, Georgia. 2. submitted on October 12, 2025. • Andrew Ruppenstein was the editor who published this page.