What is Costilla County, Colorado?
{{Infobox U.S. county | county = Costilla County | state = Colorado | seal = | ex image = Costilla County Courthouse May 2020.jpg | ex image cap = The Costilla County Courthouse in San Luis | founded year = 1861 | founded date = November 1 | seat wl = San Luis | largest city wl = San Luis | city type = town | area_total_sq_mi = 1230 | area_land_sq_mi = 1227 | area_water_sq_mi = 3.4 | area percentage = 0.3% | census estimate yr = 2020 | pop = 3499<ref name=2020Census>{{cite web|url=https://www.census.gov/quickfacts/fact/table/costillacountycolorado/PST045219|title=U.S. Census Bureau QuickFacts |access-date=September 4, 2021|publisher=[[U.S. Census Bureau]]}}</ref> | density_sq_mi = 2.9 | time zone = Mountain | footnotes = Colorado's first permanent settlement | web = costillacounty.colorado.gov | district = 3rd }} '''Costilla County''' is a [[County (United States)|county]] in the [[U.S. state|state]] of [[Colorado]] in the [[United States]]. As of the [[2020 United States Census|2020 census]], 3,499 people lived there.<ref name=2020Census/> The [[county seat]] is [[San Luis, Colorado|San Luis]]. It is the ninth-least populous county in Colorado. ==References== {{reflist}} [[Category:Colorado counties]] [[Category:1861 establishments in Colorado Territory]] {{US-geo-stub}}