County facts · Population · October 25, 2026
New Mexico Population by County, 2025 Census Estimates
New Mexico population by county: July 2025 Census estimates for all 33 counties, change since 2020, density, and a link to each official parcel map.
Looking for New Mexico population by county? The Census Bureau estimates that New Mexico had 2,125,498 residents on July 1, 2025, spread across 33 counties. Bernalillo County is the most populous, with 667,601 people (31% of the state), and Harding County is the least populous, with 617.
The table below lists every county with its 2025 estimate, its April 2020 starting point, the change, people per square mile, and a link to its official parcel viewer.
New Mexico population at a glance
- Counties: 33
- Statewide, July 1, 2025: 2,125,498 (April 1, 2020 estimates base: 2,117,492; change +8,006, +0.4%)
- Most populous: Bernalillo County (667,601); least populous: Harding County (617)
- Median county: about 26,260 residents (half of the counties are smaller)
- The 5 largest counties hold 63% of all New Mexico residents
- Counties with 1,000,000+ residents: 0 · 100,000+: 5 · under 10,000: 8
- Statewide density: about 18 people per square mile of land
New Mexico population by county, July 2025 (all 33)
Percent change runs from the April 1, 2020 estimates base to July 1, 2025. People per square mile is the July 2025 estimate divided by the county's land area in the Census Bureau's 2020 Gazetteer file, so lakes and bays are left out.
How New Mexico's population is spread out
Grouping the counties by size shows how concentrated the state is:
| Residents (July 2025) | Counties | Total residents | Share of state |
|---|---|---|---|
| 250,000 to 999,999 | 1 | 667,601 | 31% |
| 100,000 to 249,999 | 4 | 665,903 | 31% |
| 25,000 to 99,999 | 13 | 647,899 | 30% |
| 10,000 to 24,999 | 7 | 113,383 | 5% |
| Under 10,000 | 8 | 30,712 | 1% |
1 county with at least 250,000 residents holds 31% of the state's population.
Most and least densely populated
The most crowded counties by people per square mile of land:
- Bernalillo County: 575 per sq mi (667,601 people on 1,161 sq mi)
- Los Alamos County: 178 per sq mi (19,407 people on 109 sq mi)
- Santa Fe County: 82 per sq mi (156,907 people on 1,910 sq mi)
- Valencia County: 77 per sq mi (82,013 people on 1,067 sq mi)
- Doña Ana County: 60 per sq mi (229,091 people on 3,808 sq mi)
The most thinly settled:
- Harding County: 0.3 per sq mi (617 people on 2,125 sq mi)
- Catron County: 0.6 per sq mi (3,827 people on 6,924 sq mi)
- De Baca County: 0.7 per sq mi (1,647 people on 2,323 sq mi)
- Union County: 1.0 per sq mi (3,844 people on 3,825 sq mi)
- Hidalgo County: 1.1 per sq mi (3,929 people on 3,439 sq mi)
About these numbers
- They are estimates. Between censuses the Census Bureau's Population Estimates Program updates county totals each year from births, deaths and migration records. The next full count is the 2030 census.
- The base is April 1, 2020. The estimates start from an April 1, 2020 "estimates base" built from the 2020 census, which is why it is slightly different from the published census count.
- Each new release revises the past. A newer vintage can change earlier years as well, so compare numbers from the same release, as this page does.
- Statewide total. The counties add up exactly to the statewide figure of 2,125,498 in the same file.
Using population numbers in a land search
- Big counties, busy offices. In the most populous counties, parcel maps and deed records are usually online and searchable, but recording and permit offices are busier. Allow for that if you are on a deadline.
- Small counties, fewer sales. In counties with only a few thousand people, land changes hands less often, so there are fewer recent sales to compare a price with. Recorded deeds and the local assessor's sales records are the best source.
- Density hints at lot size. A low people-per-square-mile figure usually means farms, ranches and timber tracts; a high one means subdivided lots. The parcel viewer shows the actual parcel lines.
- Check the official map. Use the parcel viewer link in the table for boundaries, parcel numbers and owner names, then confirm anything important with the local assessor and the office that records deeds.
Related guides
- Fastest growing counties in New Mexico
- Largest counties in New Mexico
- New Mexico county GIS websites by viewer
- New Mexico landowner maps for hunting
- Most populous counties in the US
- Where people are moving in the US
More: All New Mexico counties on Platbookmapper
Sources
- U.S. Census Bureau, Population Estimates Program, county totals, Vintage 2025 (April 1, 2020 estimates base and July 1, 2020–2025 estimates, with components of change). Statewide totals are the sum of the counties and match the file's state row.
- U.S. Census Bureau Gazetteer files, 2020 county land and water area (for people per square mile).
- Platbookmapper county GIS directory (live data file behind our county pages, pulled October 25, 2026) for each official parcel viewer.