Geology & Natural History

In 1869 and 1871, John Wesley Powell led two expeditions from Wyoming Territory down the Green and Colorado rivers. These and other explorations brought him to a profound understanding of how the West’s aridity limits its economic prospects. He directed the U.S. Geological Survey from 1881-1894, and his ideas still affect land and water policy today. 

Mountaineer Finis Mitchell shared his love of the Wind River Range through postcards, public talks and a famed, hip-pocket hiking guide. He ran a fishing camp, worked on the railroad, stocked mountain lakes with fingerling trout and served in the Wyoming House of Representatives. Mitchell Peak was named in his honor. 

Recent, surprising discoveries including a prehistoric village in the Wind River Range above Dubois, Wyo., suggest humans—most likely ancestors of today’s Shoshone people—lived high-mountain lives as long as 10,000 years ago. 

Three total solar eclipses have crossed Wyoming since territorial times—in 1878, 1889 and 1918. Two in particular drew prominent astronomers and scientific discoveries. These are especially interesting now, with the August 21, 2017 eclipse likely to draw huge crowds to a very different Wyoming from the one that last saw moon shadows in daytime.

No logging, no grazing—even no trespassing? The Yellowstone Timber Land Reserve, the first land to be set aside in what evolved into today’s National Forest system, had a distinctly different character from its successors. Here’s why.

Iced drinks on the Oregon Trail? Early emigrants refreshed at the fabled Ice Springs near the Sweetwater River—now known as Ice Slough. But after a decade of trailside chopping and trampling, the spot became less attractive. Later travelers felt deceived by the stories they had heard.

Mixed-race families in early Wyoming appear to have sold oil skimmed from seeps to travelers on the emigrant trails, who used the oil to lubricate their wagon axles. It was a small start for what has become the huge petroleum business, so important to Wyoming today.

Natrona County’s Salt Creek Field is best known of Wyoming’s early oil fields, but five others—two in Park County and one each in Hot Springs, Niobrara and Converse counties—played important roles in the state’s 20th century transformation from an agricultural to an industrial economy.

Wyoming's fossils have been important to science since the 1870s and continue to be useful today. Remains of Triceratops, Diplodocus, Tyrannosaurus and others have helped answer—and raise—many questions about the ancient history of the planet and have captured popular imagination with their size or fierce appearance. The scientific value of these fossils and the public interest in them has brought collectors who excavate fossils and ship them to museums all over the country for further study and display. Only a few major finds from Wyoming have remained in the state.