Geology & Natural History

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.

The basin of the North Platte River takes up the southeastern quarter of Wyoming, plus a finger of land along the tributary Sweetwater River in the center of the state. The courses of the North Platte and Sweetwater determined early fur-trade and emigrant routes. Since that time, the basin’s water and other resources have continued to draw industry, stock raising, dams and irrigation—and people.

Natural gas has been flowing from the Jonah Field and Pinedale Anticline in western Wyoming since the early 1990s, bringing with it substantial profits, tax revenues, prosperity, social change, air pollution, and declines in local mule-deer populations. The story goes to the heart of Wyoming’s oil and gas culture, and raises important questions about energy production’s long-term costs and benefits.

Western Wyoming’s Green River drains 4,000 miles of forested mountains and high desert, home to migrating wildlife, grazing cattle, a few thousand people, and in recent decades a booming natural-gas business. Since prehistoric times, people have worked to balance the basin’s resources for their own benefit — and that struggle continues today.

In 1843, explorer John C. Frémont reported coal in what’s now southwest Wyoming. In the 1860s, the route of the new transcontinental railroad across Wyoming was chosen partly to access abundant coal deposits for fuel for the locomotives. Coal mining boomed, labor strife increased and Wyoming’s coal industry thrived despite worker strikes and a number of horrific mine accidents. Today, the state produces 40 percent of the nation’s coal, most of it from huge strip mines in the Powder River Basin in northeast Wyoming, for rail shipment to electric power plants in 34 states.

Wyoming’s bone-dry Bighorn Basin is isolated by its surrounding mountains and watered by crucial rivers and streams. Its history and natural history are rich with discoveries of dinosaurs, oil and gas, and with the traces of its occupants—American Indians, ranch and farm families, railroad families and oil workers.

Samuel H. “Doc” Knight taught geology at the University of Wyoming in Laramie, Wyo. from 1916 until his retirement in 1963. For a decade he was the only geology teacher, but as his classes began to grow in size and popularity the geology department expanded into a nationally recognized program. He established the university’s science camp in the mountains west of Laramie and revitalized the university’s geological museum. Knight taught an estimated 10,000 students throughout his career and was known to many “Mr. Geology of Wyoming.”

The earliest people appear to have come to Wyoming from Asia about 11,000 years ago and archaeologists now think there’s a good chance the people were direct ancestors of Shoshone people who live in Wyoming now. In recent years, the mostly white archaeologists have realized it makes sense to ask Shoshone people for help understanding the pictures and carvings their ancestors left on the rocks.

Medicine Lodge State Archaeological Site, northeast of Hyattville, contains pictographs and petroglyphs left by Wyoming’s ancient people, as well as an attractive, state-run campsite and small museum. Archaeologists have found evidence at the site of human habitation stretching back 10,000 years.