Geology & Natural History

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.

The story of uranium in Wyoming is a high-stakes drama whose cast includes fever-driven prospectors, ranchers defending their property rights, government officials intent on national security, entrepreneurs, engineers and world-class mining companies.

When Thomas Boylan started collecting dinosaur bones on his homestead in 1915, he first envisioned completing a dinosaur skeleton and using it to attract customers to his gas station on U. S. Highway 30 near Como Bluff. However, he was told that he didn’t have enough bones for that. Instead, he used more than 5,700 bones to build a structure that has become known worldwide as the Fossil Cabin. The historic Fossil Cabin was built in 1932 and stands about five miles east of Medicine Bow, Carbon County, Wyo. The cabin has been featured in Ripley’s Believe It or Not! and is listed on the National Register of Historic Places.

The Powder River Basin sports a colorful history. Bones of bison slaughtered by people, found south of Sundance, Wyo., date back 6,000 years, and northeast Wyoming remained a favorite hunting ground for American Indians into the late 19th century. At that time the Powder River Basin was the scene of violent conflicts between the Indians and U.S. military men. Abundant grass made this region a favored spot for cattle and sheep ranchers. Under the grass is coal—so much of it that about 40 percent of the coal mined in the U.S., comes from the Powder River Basin.

Oil seeps were reported often in the early 19th century in what later became Wyoming; it was sold, for example to Oregon Trail travelers for wagon lubricant. The first producing well in Wyoming Territory was drilled in 1883 at Dallas Dome southeast Lander. Perhaps the state’s best-known historic oil producing region is the Salt Creek Field, north of Casper, which was one of the world’s largest-producing fields in the 1920s. Oil remains an important part of Wyoming’s economy and culture today, and the state is ranked high among the top national producers.