Among the indigenous people who inhabited Wyoming before the Europeans came were the Lakota, the Crow, the Arapaho, and the Shoshone. This area was governed by the Spanish Empire, Mexico, and Alta California. The land was ceded to the United States after the Mexican American War in 1848. It was explored by French trappers, Lewis and Clark, and Jim Bridger. Their early descriptions of Yellowstone were widely considered to be fictitious.

Settlers followed the Oregon Trail across Wyoming on their way to the Pacific Coast, and homesteading encouraged smaller farmers to compete with the big ranchers for land use, leading to the Johnson County War in 1892. Territorial governments awarded women votes early on and elected many early women leaders, thus winning Wyoming the nickname, the Equality State.

This guide offers a selection of resources and strategies for Wyoming local history and genealogy research. These include the print and digital collections of the Library of Congress, as well as external repositories and web sites key to finding forebears in Big Wyoming, the Cowboy State.