Los Alamos County, New Mexico

Los Alamos County population, land area and income

Los Alamos County had 19,675 residents in the Census Vintage 2024 estimate, on 109.1 square miles of land. It ranks 20th of 33 in New Mexico by population and 33rd by land area. That works out to 180.3 people per square mile, 1.9 times the US average of 96.3, and in the top quarter nationally.

The median county-equivalent in New Mexico has 26,428 residents; Los Alamos County is somewhat smaller.

Its SAIPE 2023 median household income of $146,208 is the 4th highest among 3,143 counties with an estimate.

How Los Alamos County's population changed since 2020

Los Alamos County gained 253 residents between the July 2020 and July 2024 estimates, a rise of 1.3%. That ranks 9th of 33 in New Mexico for growth. The median New Mexico county changed by -1.3%, and the state as a whole by +0.5%.

Since the April 2020 estimates base, Los Alamos County recorded 682 births and 646 deaths, a natural change of +36. Net international migration added +606 and net domestic migration, people moving to or from other US counties, came to -406. The largest single component was international migration, which added 606 people.

Where Los Alamos County is

The Census internal point of Los Alamos County is at 35.870000, -106.308000. It sits in UTM zone 13N. The map shades New Mexico's 33 county-equivalents by population change from 2020 to 2024, darker for faster growth, with Los Alamos County outlined. Dots are towns of 1,000+ people with residents in it.

Towns in Los Alamos County

No incorporated place of 1,000 or more people has residents in Los Alamos County. Its 19,675 residents live in smaller towns, census-designated places, or unincorporated land, which the subcounty estimates do not list at this size.

Counties bordering Los Alamos County

The Census 2024 county adjacency file lists 3 neighbors for Los Alamos County. The most populous is Santa Fe County, NM, with 157,765 residents. Distances run between Census internal points in a straight line.

• Santa Fe County

  157,765 people

  31 mi SE

• Sandoval County

  157,757 people

  35 mi WSW

• Rio Arriba County

  39,955 people

  49 mi NNW

Distance to Santa Fe and the nearest big city

Santa Fe is 24.4 miles ESE of Los Alamos County's internal point in a straight line. The nearest place of 100,000 or more is Rio Rancho, NM (population 112,524), 46.0 miles away. The nearest place of 10,000 or more is Española, NM (population 10,475), 16.2 miles away.

Los Alamos County FIPS code

The FIPS code of Los Alamos County is 35028: state code 35 for New Mexico plus county code 028. Use it as text, with the leading zero, when joining Census, BLS, or CDC county tables. SAIPE lists its 2023 median household income as $146,208.