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

Because Colorado was a land of extreme elevation changes, its pre-colonial population was characterized by "vertical migration"—nations lived at different altitudes depending on the season. This makes precise population counts difficult, but archaeological and historical records reveal a region that was far from empty.

A Landscape of High-Altitude Strategy

The geography of Colorado split the population into two distinct lifestyles: the mountain-dwelling "Highland" cultures and the "Plains" cultures of the eastern corridor.

The Population Estimates

In the late 1700s, just as European influence began to trickle into the Rockies through trade and disease, historians estimate the following:

• The Estimated Range: Between 25,000 and 50,000 people lived within Colorado’s modern borders at any given time.
• The Peak Era (c. 1100–1250 CE): Centuries before the Spanish arrived, the population in the Four Corners region of Southwestern Colorado was significantly higher. At its peak, the Mesa Verde region alone likely supported over 20,000 to 30,000 people—a density not seen again in that area until the 20th century.

The Nations of the Peaks and Prairies

Colorado was the ancestral home and hunting ground for several major groups, each utilizing the state's diverse geography with scientific precision.

The Ute (Nuuchiu)

The Ute are the oldest continuous residents of Colorado. They were masters of the mountains, occupying the vast majority of the state's western and central regions. Divided into seven distinct bands, the Utes moved into the high mountains in the summer to hunt elk and deer and descended into the warmer valleys for the winter. They were among the first to adopt the horse, which allowed them to defend their mountain strongholds for centuries.

The Arapaho (Hinono'eiteen) and Cheyenne (Tsitsistas)

By the early 1800s, the Eastern Plains of Colorado were the domain of the Arapaho and Cheyenne. These "Buffalo Nations" followed the massive herds across the shortgrass prairies. The Front Range—where the mountains meet the plains—served as a vital trade and resource zone for these groups, particularly the South Platte and Arkansas River valleys.

The Ancestral Puebloans

In the deep canyons of the Southwest, the Ancestral Puebloans built incredible masonry cities into the cliffs. While they had largely migrated south into modern-day New Mexico and Arizona by the 1300s due to drought and social shifts, their legacy and descendants (the Pueblo tribes) maintain deep spiritual connections to Colorado.

The Biological and Resource Conquest

The "conquest" of Colorado didn't wait for the 1850s. It arrived decades earlier through two major shifts:

• Epidemics: Smallpox outbreaks in the 1780s and again in the 1830s decimated the Plains tribes. Because the Arapaho and Cheyenne lived in large, socially connected bands, the virus spread rapidly, often killing 40% to 50% of a village within weeks.
• The Fur Trade: In the 1820s and 30s, the arrival of mountain men and trading posts like Bent’s Fort introduced a cash economy based on beaver pelts and buffalo robes. This changed the indigenous population's relationship with the land and introduced new dependencies and tensions between tribes.

Colorado’s Indigenous Presence Today

The 1860s were a period of extreme violence in Colorado, most notably the Sand Creek Massacre of 1864, which saw the unprovoked slaughter of peaceful Cheyenne and Arapaho people. This event led to the forced removal of the Plains tribes to Oklahoma and Wyoming.

Today, there are two federally recognized tribes that maintain a land base in Colorado: the Southern Ute Indian Tribe and the Ute Mountain Ute Tribe, both located in the southwestern corner of the state. However, the presence of the 48 tribes historically tied to Colorado is felt across the state, from the names of the mountains to the ongoing efforts to protect the sacred water of the Colorado River.