According to theU.S. Census Bureau, the county has a total area of 109 square miles (280 km2), of which 109 square miles (280 km2) is land and 0.09 square miles (0.23 km2) (0.08%) is water.[5] It is the smallest county by area in New Mexico. There is no significant open water in the county. The county's highest point is located along its northern border, near thesummit of Caballo Mountain, at 10,480 feet (3,190 m) abovesea level.
As of the2010 census, there were 17,950 people, 7,663 households, and 5,199 families living in the county.[11] The population density was 164.4 inhabitants per square mile (63.5/km2). There were 8,354 housing units at an average density of 76.5 units per square mile (29.5 units/km2).[12] The racial makeup of the county was 87.8% white, 6.0% Asian, 0.8% American Indian, 0.6% black or African American, 0.1% Pacific islander, 2.2% from other races, and 2.6% from two or more races. Those of Hispanic or Latino origin made up 14.7% of the population.[11] In terms of ancestry, 18.9% were ofGerman origin, 16.5%English, 13.2%Irish, and 6.5% wereAmerican.[13]
Of the 7,663 households, 31.3% had children under the age of 18 living with them, 58.1% were married couples living together, 6.4% had a female householder with no husband present, 32.2% were non-families, and 28.5% of all households were made up of individuals. The average household size was 2.33 and the average family size was 2.86. The median age was 44.3 years.[11]
The median income for a household in the county was $103,643 and the median income for a family was $118,993. Males had a median income of $93,040 versus $51,753 for females. The per capita income for the county was $49,474. About 1.4% of families and 2.4% of the population were below thepoverty line, including 1.8% of those under age 18 and 2.4% of those age 65 or over.[14]
As of the2000 census,[15] there were 18,343 people, 7,497 households, and 5,337 families living in the county. Thepopulation density was 168 people per square mile (65 people/km2). There were 7,937 housing units at an average density of 73 units per square mile (28/km2). The racial makeup of the county was 90.3%White, 0.4%Black orAfrican American, 0.6%Native American, 3.8%Asian, <0.1%Pacific Islander, 2.7% fromother races, and 2.3% from two or more races. 11.8% of the population wereHispanic orLatino of any race.
There were 7,497 households, out of which 33.5% had children under the age of 18 living with them, 62.7% weremarried couples living together, 5.7% had a female householder with no husband present, and 28.8% were non-families. 24.9% of all households were made up of individuals, and 6.7% had someone living alone who was 65 years of age or older. The average household size was 2.43 and the average family size was 2.92.
In the county, 25.8% of the population was under the age of 18, 4.4% was from 18 to 24, 27.7% from 25 to 44, 30.0% from 45 to 64, and 12.1% was 65 years of age or older. The median age was 41 years. For every 100 females there were 101.40 males. For every 100 females age 18 and over, there were 99.70 males.
The median income for a household in the county was $78,993, and the median income for a family was $90,032. Males had a median income of $70,063 versus $40,246 for females. Theper capita income for the county was $34,646. 2.9% of the population and 1.9% of families were below thepoverty line. 1.8% of those under the age of 18 and 4.7% of those 65 and older were living below the poverty line.
The county council was created by the Los Alamos County Charter. The council consists of seven members elected at large for four-year, staggered terms. Each year the seven councilors select the new chair and vice chair.[16]
In a study conducted byAmerican City Business Journals in 2004, Los Alamos County topped the list as the best place to live in the United States in terms ofquality of life. This was attributed to the high levels of job stability, income and education of Los Alamos residents, many of whom are employed as scientists and engineers at theLos Alamos National Laboratory. The county has one of the highest number of PhDs per capita and the 2011median household income of $110,204 per year is the second highest among all the counties in the U.S. In per capita income, Los Alamos County ranks1st in New Mexico and 7th in the United States, and has the second-lowest level of poverty in the United States, and the lowest level of child poverty.[4] Other factors contributing to Los Alamos's high quality-of-life index were the access to affordable housing and short commuting times.
A map of the most college-educated counties in the United States
Los Alamos County is one of the most highly educated counties in the United States. More than 60% of adult residents over the age of 25 have bachelor's degrees, over 40% have a graduate degree, and nearly 20% have aPhD. To put this in perspective, the county is more highly educated than theDistrict of Columbia, the nation's capital.[18]
Both Los Alamos County and theLos Alamos National Laboratory are trying to reduce their respectivecarbon emissions[20] in order to help mitigate the continually worsening dangers ofclimate change.[22] In 2015, Los Alamos County joined with the Utah Associated Municipal Power Systems in theCarbon Free Power Project.[23] The Project planned to useNuScale Power’s Small Module Reactor design to provide nuclear energy to counties across theUnited States, but was cancelled in 2023 because of cost increases.[24] Los Alamos’ history is tied tonuclear energy, which has an environmental impact comparable to that ofrenewables as a source of domestic power.[25] This is true of both large and small modulereactors.[26]
Formerly solidly Republican, Los Alamos County has voted Democratic since2008. In2024, Democratic nomineeKamala Harris won the highest percentage of the vote in the county since1964.
It has seen high percentages of third-party votes in years with major third-party candidates, such as withJohn B. Anderson in1980,Ross Perot in1992 and1996, andGary Johnson in2012 and2016. Los Alamos County had the highest percentage of support for Johnson in New Mexico in 2016, at 13.89% (a total of 1,512 votes out of 10,885 cast).[27]
United States presidential election results for Los Alamos County, New Mexico[28]
^abChambers, Marjorie Bell (1999).The Battle for Civil Rights or How Los Alamos Became a County. Los Alamos, New Mexico: Los Alamos Historical Society.ISBN0-941232-23-9.
^"Find a County". National Association of Counties. RetrievedJune 7, 2011.
^Cissé, G., R. McLeman, H. Adams, P. Aldunce, K. Bowen, D. Campbell-Lendrum, S. Clayton, K.L. Ebi, J. Hess, C. Huang, Q. Liu, G. McGregor, J. Semenza, and M.C. Tirado, 2022: Health, Wellbeing, and the Changing Structure of Communities. In: Climate Change 2022: Impacts, Adaptation and Vulnerability. Contribution of Working Group II to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change [H.-O. Pörtner, D.C. Roberts, M. Tignor, E.S. Poloczanska, K. Mintenbeck, A. Alegría, M. Craig, S. Langsdorf, S. Löschke, V. Möller, A. Okem, B. Rama (eds.)]. Cambridge University Press, Cambridge, UK and New York, NY, USA, pp. 1041–1170, doi:10.1017/9781009325844.009. Retrieved May 5, 2023.
