Formed November 1, 1861 (4th county)
Costilla County (3,496), San Luis (600)
A Classical style stucco structure built in 1884 serves as the Costilla County courthouse. The facility is located on Main Street between 4th and Gaspar streets in this small town. John Farrington and Samuel Tucker provided the building designs. A small tower sits on top of the facility. The courthouse was renovated in 2008. San Luis is the oldest town in Colorado and has been the only county seat. Colorado State Highway 159 is Main Street through the town. Costilla County was one of the original counties established on November 1, 1861. It is the 4th county. Saguache, Hinsdale, Rio Grande, and Alamosa counties were cut from part of Costilla County. Costilla County was named for the Costilla River which is Spanish for “little rib” or “furring timber.” San Luis is named for the San Luis Valley. The center of the county is 9.7 miles Northwest of San Luis.
Costilla County government consists of a sheriff, assessor, manager, coroner, and treasurer (executive). It has 3 Commissioners (legislative.) Four District Court Judges serve Costilla, Alamosa, Conejos, Mineral, Rio Grande, and Saguache counties and a Trial Court Judge, clerk, and county attorney serve Costilla County (judicial.) The county is in south Colorado on the border with New Mexico. The Rio Grande forms its western border. The county is surrounded clockwise by Huerfano and Las Animas counties and New Mexico and Conejos and Alamosa counties.
The area of the county is 1229.4 square miles. The county is 38 out of 64 in the state. It ranks 56 out of 64 in population in the state. It has a density of 2.8 persons per square mile making it 51 out of 64 in the state. Costilla County has 26.4% of its population in its incorporated areas. United States Highway 160 crosses the northern part of the county from east to west, Huerfano County to Alamosa County. A bag of popcorn with the northwest corner missing describes the county’s shape. San Luis is located in the southern third of the county. San Luis is the county seat and the largest city. It is 17.2% of the county population. The county is pronounced KOS-TEE-YA. The county seat is pronounced SAN LUE-EES.
Blanca
San Luis
