How many people live in Costilla County, CO?
Updated Apr. 6, 2026Refreshed annually
In 2024, there were about 3,700 people living in Costilla County, CO. That makes Costilla County the 55th-most populous county in Colorado. It is home to 0.06% of people living in the state.
3.69K
population of Costilla County, CO (2024)
0.06%
County share of the Colorado population (2024)
About 3,700 people lived in Costilla County, CO in 2024.
Population estimates, 2000–2024
What are Costilla County, CO’s age demographics?
About 1,100 Costilla County residents are aged 65 and older in 2024. That represents 29.4% of its population. For comparison, the age group represents 16.5% of Colorado’s population and 18% in the US overall.
Another 682 Costilla County residents, or 18.5% of the population, were children under 18. For comparison, the age group represents 20.5% of Colorado’s population and 21.6% in the US overall.
A higher share of Costilla County, CO's population is aged 65 or older than the US as a whole.
Population estimates by age group, (2024)
What are Costilla County, CO’s racial and ethnic demographics?
Hispanic residents make up 53.2% of the Costilla County, CO population, higher than the national share of 20%. Costilla County also has a larger share of people identifying as non-Hispanic American Indian and Alaska Native (2.1%) than the US overall (0.72%).
In contrast, Costilla County’s non-Hispanic white population accounts for 38.6%, below the 57.5% nationwide, and the non-Hispanic Black or African American population makes up 2.6% of the county, compared with 12.6% nationally.
Racial and ethnic make up differ based on location. These figures reflect how people identified their race alone (not in combination with other races), and separate out Hispanic or Latino ethnicity, following Census reporting standards.
Costilla County, CO has a higher share of a Hispanic population than Colorado as a whole.
Population estimates by race and ethnicity, (2024)
The largest city or town in Costilla County, CO is San Luis with about 628 residents in 2024.
Cities and towns in Costilla County, CO ranked by population
Population (2024), includes only portions within county
| City or town | Population | |
|---|---|---|
| 1. | San Luis | 628 |
| 2. | Blanca | 342 |
| 3. | Balance of Costilla County | 2,716 |
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Methodology
USAFacts standardizes data, in areas such as time and demographics, to make it easier to understand and compare.
The analysis was generated with the help of AI and reviewed by USAFacts for accuracy.
Page sources
USAFacts endeavors to share the most up-to-date information available. We sourced the data on this page directly from government agencies; however, the intervals at which agencies publish updated data vary.
