Dolores County was created by the Colorado legislature on February 19, 1881, from the western portions of Ouray County, and was named for the Dolores River, which heads up in the county and passes through the county in the Dolores Canyon. The complete Spanish name was Rio de Nuestra Señora de los Dolores (River of our Lady of Sorrows), as reported by Father Silvestre Vélez de Escalante in 1776.
Originally set in Rico, the first county courthouse was a 23x48 foot two storage log cabin, but was replaced by a stone and brick courthouse completed in 1883. the county seat was moved to Dove Creek in 1946, and the current courthouse built in 1957.