Costilla County, Colorado

Costilla County, Colorado
The Costilla County Courthouse in San Luis
Location within the U.S. state of Colorado
Coordinates: 37°17′N 105°26′W / 37.28°N 105.43°W / 37.28; -105.43
Country United States
State Colorado
FoundedNovember 1, 1861
SeatSan Luis
Largest townSan Luis
Area
 • Total
1,230 sq mi (3,200 km2)
 • Land1,227 sq mi (3,180 km2)
 • Water3.4 sq mi (8.8 km2)  0.3%
Population
 (2020)
 • Total
3,499
 • Estimate 
(2024)
3,686
 • Density2.852/sq mi (1.101/km2)
Time zoneUTC−7 (Mountain)
 • Summer (DST)UTC−6 (MDT)
Congressional district3rd
Websitecostillacounty.colorado.gov
Colorado's first permanent settlement

Costilla County (Spanish for "rib") is a county located in the U.S. state of Colorado. As of the 2020 census, the population was 3,499. The county seat is San Luis, the oldest continuously occupied town in Colorado.