Costilla County is named for the Costilla River which is named for the Spanish word “Costilla” which means “little rib” or “furring timber”.
Surrounding County Courthouses:
N – Huerfano County
E – Huerfano County and Las Animas County
S – Colfax County, New Mexico and Taos County, New Mexico
W – Conejos County and Alamosa County
Created: November 1, 1861 
County Seat:
San Miguel 1861 – 1863
San Luis 1863 – present
County Courthouse – San Luis
Location: 304 Main Street / Gaspar Street
Built: 1883 – 1884
Style: Classical
Architect: John Farrington, Samuel Tucker and others
Contractor: John Farrington, Samuel Tucker and others
Description: The building faces west and is a one story stone and stucco structure. The building is located on landscaped grounds in the center of San Luis. The west front has a recessed entrance in the center. At the center of the roof is a square wood cupola with green colored roof. The roof is sloped. The building houses the County District Court and County Court of the 12th Judicial District. The building was renovated in 2008. The architect was Gifford Spurch and Associates and Albert Moore & Associates and the contractor was Crocker Limited and Upscale Builders, Inc.
Note: In 1861, Costilla County was one of the 17 original counties.
See: The 12th Judicial District includes Alamosa County, Conejos County, Mineral County, Rio Grande County and Saguache County.
History: The county was created in 1861 and San Michael was selected as the county seat. The county seat was moved to San Luis in 1863. The county used rented premises. The first and present courthouse was constructed in 1883 to 1884.
County Courthouse – San Luis
Photos taken 2011