Population estimates of as many as 10,000 inhabitants, with villages containing hundreds of rooms, have been discovered by archaeologists and other researchers.

According to the Anasazi Heritage Center, Dolores County contains at least 816 recorded archaeological sites as of 1989, with many more inventoried since that time.

The trail marks a historic 1,800-mile (2,900 km) trip, intended to discover an overland route between Santa Fe, New Mexico and Monterey, California.

The development of the area was spurred by the discovery of large silver deposits near Rico in 1879, and the Rio Grande Southern Railroad was constructed through the county to connect Durango, Telluride, and Ridgway in 1890-92 The RGS served the eastern end of Dolores County until 1952 when it was abandoned.

Efforts are underway in the early 21st Century to again begin major mining activities in the region.

Dove Creek was a way station on the Old Spanish Trail from the mid 19th century, for caravans and travelers moving between Santa Fe, Salt Lake City, and northern California and Nevada.

The western portion of the county was used, beginning in the 1870s, for cattle ranching, but the lush grass soon suffered from overgrazing and then fire suppression, allowing the massive expansion of sagebrush, pinyon, and juniper.

Homesteading in the area became common beginning in 1914, and dryland farming expanded throughout the Great Sage Plain.

Today dryland farming of pinto beans and winter wheat is still a mainstay of the county's economy.

(The original county courthouse in Rico is now the town hall and a branch of the public library.)

The western portion of the county (east of the Dolores River Canyon and along the Utah border) is the northern portion of the Great Sage Plain, relatively low 6,500–7,500 ft (2,000–2,300 m) in elevation and flat (but cut by large canyons, including that of the Dolores River itself), and consists of irrigated and dryland farming areas; it is especially well known for the cultivation of various varieties of beans, including pinto beans and many variety of old Anasazi beans.

The central portion of the county has higher open grasslands with forested hills, ravines, and canyons, used for livestock raising.

The eastern portion of the county is located in the highest peaks of the San Juan Mountains, around the old mining and modern tourist town of Rico, and except for cattle grazing in the San Juan National Forest, has virtually no agriculture, in part because its elevations range from 9,000 to 14,000 ft (2,700 to 4,300 m).

Rico is developing in many ways as a bedroom community for the much wealthier town of Telluride in San Miguel County to the north.