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 abundant vertebrate fossils of the Green River formation in western Wyoming have been known to science since the 1860s. Most are fish, buried in lime-rich mud at the bottom of freshwater lakes about 50 million years ago. Fossil Butte National Monument, west of Kemmerer, Wyo. was created by Congress in 1973 to protect a site extremely rich in these fossils.

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.

Remains of at least seven mammoths, probably from a meat cache dating back more than 11,000 years, were found when the Colby Mammoth site east of Worland, Wyo., was excavated by a crew under Wyoming State Archaeologist George Frison in the 1970s.

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.