Doña Ana County area

Population and density of Doña Ana County

The Census Bureau estimates that 229,091 people lived in Doña Ana County on July 1, 2025. That ranks #315 of 3,222 county equivalents nationally and #2 of 33 in New Mexico. Since the April 1, 2020 estimates base of 219,563, the population has grown by 9,528 (+4.3%), compared with +0.4% for New Mexico as a whole.

With 3,808.2 square miles of land, that is 60 people per square mile (23 per km²), placing Doña Ana County #1,385 nationally for density and #5 in New Mexico. The median county equivalent has 47 people per square mile; the New Mexico median is 6.9. Put another way, there are about 11 acres of land per resident.

U.S. Census Bureau, Vintage 2025 population estimates. Estimates are revised each year and are not decennial census counts. Density divides the whole population by the whole county’s land area, so it describes an average, not how settlement is distributed within the county. Population sources and methods.

Cities and towns in Doña Ana County

5 incorporated places lie at least partly in Doña Ana County. Together they are home to 147,548 people (64.4%); the other 81,543 (35.6%) live outside any incorporated place, in unincorporated communities and rural areas.

The largest is Las Cruces city, with 116,978 residents in the county. Among places with at least 1,000 residents in 2020, Sunland Park city grew fastest since then (+9.3%).

Population: U.S. Census Bureau Vintage 2025 subcounty estimates, counting only the part of each place inside Doña Ana County. Land: 2026 Census Gazetteer, for the whole place even where it extends into other counties. How communities are listed.

Metropolitan area

Doña Ana County is a central county of the Las Cruces, NM Metropolitan Statistical Area. Doña Ana County is the area’s only county equivalent, so the metro area has the same 3,808.2 square miles of land. By combined land it ranks #77 of 393 metropolitan areas, and #212 by population. It belongs to the El Paso-Las Cruces, TX-NM Combined Statistical Area.

ZIP codes

26 ZIP Code Tabulation Areas have land in Doña Ana County; 23 of them have most of their land inside the county, and the others mainly cover neighboring areas.

7983579922879368793787940879418800188002880038800488005880078800888011880128802188024880278804488046880478804888052880638807288081

ZIP Code Tabulation Areas are the Census Bureau’s approximations of USPS ZIP Code service areas, from the 2020 Census relationship files. Lighter codes have less than half of their land in this county. Post-office-box and single-address ZIP Codes have no tabulation area.

Counties bordering Doña Ana County

Doña Ana County shares a land border with 4 county equivalents, including 1 in Texas. It has more land than 2 of them. The largest neighbor is Otero County (6,612.6 mi²) and the smallest is El Paso County (1,013.5 mi²). Together with its neighbors, Doña Ana County forms a block of 18,580.7 mi² of land, of which it holds 20.5%.

How big is Doña Ana County compared with U.S. states?

Doña Ana County has more land than 2 of the 50 states. It is about 2 times the land area of Delaware (1,948.6 mi²), while Connecticut, the next larger state, has 1.3 times as much land (4,842.5 mi²). New Mexico’s county land could hold about 32 areas the size of Doña Ana County.

Another way to picture it: the same land area would fill a square about 61.7 miles (99.3 km) on each side. Real county shapes are rarely square, so this is a scale reference rather than a width or driving distance.

State figures are the sums of each state’s county-equivalent land measurements in the same Census release, so states and counties are compared on the same basis. Published state totals can differ slightly because of rounding. Compare all states · Counties bigger than entire states.

What stands out about Doña Ana County?

Doña Ana County has more land than 3,091 of the other 3,221 county equivalents in the dataset.

A median is the middle county-equivalent measurement, not the average of the largest and smallest. All three bars use the same linear scale. Very small areas may appear as a thin sliver; the labels retain their values.

Does including water change its rank?

Using land plus water places Doña Ana County at #138 nationally by total area, 7 places farther from the top than its land rank. Other county equivalents gain more area when their water measurements are included.

Its water share is 0.2%, compared with a national county-equivalent median of 1.2% — 1 percentage points lower. This describes the statistical geography’s land/water mix, not flood exposure or developable land.

Closest positions in the national land ranking

These entries sit immediately beside Doña Ana County in the national ranking. They can be in different states and are not necessarily geographic neighbors.

Calculated from the same Census release as the area table. Total-area order uses original ALAND + AWATER; water shares and chart labels use published square miles. Calculation details.