Costilla County, Colorado

Costilla County
The Costilla County Courthouse in San Luis
Location within the U.S. state of Colorado
Colorado's location within the U.S.
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 (9 km2)  0.3%
Population
 (2020)
  Total
3,499
  Estimate 
(2024)
3,686
  Density2.8/sq mi (1.1/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.