How Many Native Americans Lived in Wyoming Before the Colonial Conquest?

Because Wyoming’s climate is characterized by extreme winters and vast, arid basins, its pre-colonial population was highly mobile. These nations did not build permanent stone cities like those in the Southwest; instead, they lived in a "seasonal round," following the migrations of the great bison herds.

A Land of High-Plains Mobility

Pre-colonial Wyoming was a land of movement. Because the environment was too harsh for large-scale agriculture, the population density was lower than in the river valleys of Washington or the coast of Oregon, but the people were among the most physically and diplomatically expansive on the continent.

The Population Estimates

Estimating the population of a mobile society is notoriously difficult, as tribes frequently moved in and out of what are now state lines.

• The Baseline: Historians generally estimate that between 15,000 and 30,000 Native Americans lived within the modern borders of Wyoming at any given time during the late 1700s.
• The "Gathering" Factor: These numbers would swell significantly during the summer months, as tribes from the surrounding regions of Montana, Idaho, and Colorado converged on the Wyoming plains for massive communal bison hunts and sun dance ceremonies.

The Great Nations of the Wind and Mountain

The indigenous landscape of Wyoming was primarily shaped by the interaction between the Great Basin cultures and the Plains cultures.

The Eastern Shoshone

The Shoshone (Newe) have the longest continuous presence in the Wyoming region. They were masters of the mountain-and-basin landscape, utilizing the thermal springs of the Yellowstone area and the fertile Wind River Valley. By the early 1700s, the Shoshone were among the first Northern tribes to acquire horses, which briefly made them the dominant military power on the northern plains.

The Northern Arapaho

The Arapaho (Hinono'eiteen) moved into the Wyoming region from the Great Lakes area. They became a quintessential "Plains Culture," known for their sophisticated social structures and deep spiritual traditions. They maintained a close alliance with the Cheyenne and frequently occupied the eastern and southeastern portions of the state.

The Crow, Cheyenne, and Lakota

The northern and eastern plains of Wyoming were contested and shared lands. The Apsáalooke (Crow) claimed the Powder River Basin as their heartland, while the Tsitsistas (Cheyenne) and the Oglala Lakota moved into the region as they pushed westward in the late 18th and early 19th centuries.

The Invisible Transformation: Horses and Disease

Like its neighbors, Wyoming underwent a demographic revolution long before the first wagons of the Oregon Trail appeared.

• The Equestrian Era: The arrival of the horse around 1700 allowed Wyoming’s tribes to hunt more efficiently and support larger bands. This led to a "golden age" of Plains culture but also increased the frequency of large-scale warfare over the best hunting grounds.
• The Silent Killer: Smallpox arrived in the late 1700s, likely via trade routes from the south and east. Because Wyoming was a crossroads, its inhabitants were particularly vulnerable to diseases carried by traveling groups. It is estimated that some Shoshone and Crow bands lost up to 50% of their population in the great epidemic of 1781.

Wyoming’s Indigenous Presence Today

The history of Wyoming’s first people is a story of incredible persistence. Despite the "Indian Wars" of the 1860s and 70s—including the famous Battle of the Rosebud and the Dull Knife Fight—the tribes maintained a permanent foothold in their ancestral lands.

Today, the Wind River Reservation is the seventh-largest in the United States and is home to two distinct sovereign nations: the Eastern Shoshone and the Northern Arapaho. These tribes are central to Wyoming’s economy and its environmental efforts, particularly in the management of water rights and the restoration of native wildlife like the Yellowstone bison.