5.9 - DOLORES RIVER BASIN The Dolores and San Miguel Rivers
originate in the Rico, La Plata, and San Juan Mountains of
southwest Colorado. The Dolores River basin is about 95 miles
long from northwest to southeast and encompasses an area of just
over 5,300 square miles, including parts of Montezuma, Dolores,
San Miguel, Montrose, and Mesa counties. The San Miguel River
basin is tributary to the Dolores River, is 68 miles long, and
encompasses about 1,600 square miles, including portions San
Miguel and Montrose counties. The Dolores River basin falls
within both Water Management Divisions 4 and 7. Less than 100
alluvial wells have been recorded with the State Engineer’s
Office. The occurrence and distribution of alluvium along the
Dolores and San Miguel Rivers is shown in yellow on Figure
5.9-1. Both river basins overlie substantial portions of the
Paradox Basin. Altitudes in the Dolores and San Miguel River
basins range from about 14,200 feet near the Dolores River
headwaters to 4,100 feet at their combined c