Los Alamos (, meaning 'The Poplars') is a census-designated place in Los Alamos County, New Mexico, United States, that is recognized as one of the development and creation places of the atomic bomb—the primary objective of the Manhattan Project by Los Alamos National Laboratory during World War II. The town is on four mesas of the Pajarito Plateau, and had a population of about 13,200 as of 2020. It is the county seat and one of two population centers in Los Alamos County; the other is White Rock.
Toponym Los Alamos is a Spanish place name that typically refers to poplar or cottonwood trees. Alternatively, Los Alamos could refer to the large groves of quaking aspen that intersperse the coniferous forest on the mountainsides above the townsite, where they are distinctly visible in the autumn due to their spectacular autumn colors.
History
The ruins of Puebloan settlements, such as those in nearby Bandelier National Monument and Tsankawi, and numerous other sites such as cliff dwellings indicate that the area has been inhabited during various eras since around 1150 AD. The first settlers on the plateau are thought to be Keres-speaking Native Americans around the 10th century. Around 1300, Tewa settlers immigrated from the Four Corners Region and built large cities but were driven out within 50 years by Navajo and Apache raids and by drought.
In the late 19th century, homesteaders used the land for ranching. About 1899, a road had been blasted up one of the canyons onto the Pajarito Plateau from Buckman (on the narrow-gauge Chili Line railroad) for the harvesting of timber, which in turn made the Plateau more accessible.Pettit, Roland A: Los Alamos Before the Dawn, Pajarito Publications 1972. Homesteaders built simple log cabins that they lived in only during warm weather to feed livestock. Many of the homesteaders later moved down to the warmer Rio Grande Valley. In 1917, homesteader Harold H. Brook sold part of his land and buildings to Ashley Pond II, a businessman from Detroit who founded the Los Alamos Ranch School. The area was used to teach young men basic ranching and other outdoor survival skills.
In 1943, during World War II, the United States Department of War exercised eminent domain over the Ranch School and all remaining homesteads in the area so that the relatively isolated location could be used for the secretive Manhattan Project, which developed the first nuclear weapons. Facilities for research and development were quickly built and scientists and engineers from all over the world were assigned to the project; all information about the town and project was held secret from the public. Los Alamos was referred to under the code name "Site Y" by military personnel and was known only as "The Hill" by many in nearby Santa Fe.
Los Alamos was originally built as a closed city accessible from the outside world only through two gates. The project's location was a tightly guarded secret. All employees recruited to work at Los Alamos were given a memorandum instructing them to travel to Santa Fe and report to the U.S. Army Corps of Engineers office at 109 East Palace Avenue. There, Dorothy McKibbin gave newcomers the necessary documentation to get through security checkpoints (initially, letters signed by J. Robert Oppenheimer, and later security passes), along with specific directions to the Hill. The project was further concealed by using the mailing address PO Box 1663, Santa Fe, N.M. All incoming truckloads were falsely labeled as common items to conceal the nature of their contents, and military officials censored outbound correspondence by those working and living in Los Alamos.
Not until after the bombing of Hiroshima in 1945 was information about the Manhattan Project released to the public, announced by the White House at 11 am on 6 August. A set of press releases were given out over three days.
In the years after World War II, the laboratory was formally established as a research government facility under the civilian control of the U.S. Atomic Energy Commission, and is now known as Los Alamos National Laboratory. In 1957, the AEC pulled back the security perimeter to the laboratory and opened up the town to visits by the general public. The first visitor to enter the town that year without a permit from the federal government was New Mexico Governor Edwin L. Mechem. The AEC was later succeeded by the U.S. Department of Energy.
Los Alamos served as the setting for much of the 2023 film Oppenheimer, but mostly for interior scenes. The town's appearance had changed drastically since the 1940s, so the filmmakers arranged for the construction of a set based on 1940s-era Los Alamos at Ghost Ranch and filmed exterior scenes there.
Geography Los Alamos is in northern New Mexico, between the Rio Grande and the eastern rim of the Valles Caldera on the Pajarito Plateau, about northwest of Santa Fe. The elevation at the post office is and total land area is .
The Los Alamos Townsite and White Rock are on flat mesa tops known as potreros, separated by steep canyons. This location was chosen for its relative inaccessibility to help protect the Manhattan Project's secrecy.
The town of Los Alamos was built on four potreros—Barranca Mesa, North Mesa, Los Alamos Mesa, and South Mesa—along with the connecting communities at the base of the mountain. Los Alamos National Laboratory occupies half of South Mesa, Two Mile Mesa, Frijoles Mesa, Mesita de Buey, and several nearby areas in the region (in the valleys and at the base of the mountain). White Rock lies at the top of White Rock Canyon.
Much of Los Alamos County is within the Española Ranger District of the Santa Fe National Forest.
Climate Los Alamos has a humid continental climate (Dfb) with four distinct seasons. Summer days are moderately warm in the 70s°F (20s°C), but reach 90 °F (32 °C) on only 5 days per year on average.
Wildlife and vegetation Los Alamos's wildlife and vegetation are diverse compared to surrounding areas. "The variation in elevation creates precipitation and temperature gradients that support a wide diversity of plant communities". There are six different plant communities in the county; each is home to unique flora and fauna. Ponderosa pine trees are the most common trees at the elevation of Los Alamos (). Common shrubs in the area include sagebrush, Gambel oak, and wild rose.
Black bears (brown-color variation), elk, mule deer, bobcats, gray foxes, skunks and chipmunks are examples of mammals living in the area. "Over 200 species of birds have been reported" in the Pajarito Ornithological Survey conducted by LANL. Among these are broad-tailed hummingbirds, hairy woodpeckers, zone-tailed hawks, common ravens, western bluebirds, and great horned owls.
Wildfires Wildfires have affected the county, but the most destructive to the townsite was the Cerro Grande Fire of 2000, which caused an estimated $1 billion in damages and destroyed more than 400 homes. The CDP was evacuated for eight days. The Federal Emergency Management Agency (FEMA) built temporary housing on North Mesa for those who were displaced by the fire. Though there was no loss of life, other effects include damage to LANL facilities (nuclear material was not affected), flash-flooding, and erosion.
The Las Conchas Fire of 2011 burned about three times as many acres and also prompted evacuation of Los Alamos, but there was no damage to property in Los Alamos. It was the largest recorded wildfire in New Mexico until the Whitewater-Baldy complex fire in 2012.
Wildfire (year) Burned area Cause Water Canyon Fire (1954) trash/construction debris fire La Mesa Fire (1977) human-caused Dome Fire (1996) abandoned campfire Oso Complex Fire (1998) arson Cerro Grande Fire (2000) controlled burn Las Conchas Fire (2011) Power line
Wildfires have altered plant communities in the area. Plant species are migrating to cover burn areas.
Environmental remediation Over 2,000 sites in the area have been determined to have been affected by past activities at LANL. These sites have been identified throughout the county, and are primarily (but not exclusively) on DOE property. Contaminated sites vary widely in significance. Corrective action and environmental restoration has been deemed necessary for certain areas; LANL takes part in this process. Some residents have voiced concern about a lack of public participation and opportunity to comment on the cleanup schedule and funding.
Demographics
Racial and ethnic composition Racial composition 20102020White 85.9%73.2% —Non-Hispanic 74.8%67.8% Hispanic or Latino (of any race) 14.3%17.4% Asian 7.2%8% American Indian and Alaska Native 0.8%0.7% Black or African American 0.6%1%
Los Alamos is demographically unique compared to its surrounding counties and the state as a whole. Over 35% of the population of surrounding counties (Rio Arriba, Santa Fe, and Sandoval) and the state are Hispanic or Latino, while only about 20% of Los Alamosans are Hispanic or Latino. The white and especially the Asian populations of Los Alamos are significantly higher than in the rest of New Mexico.
2020 census As of the 2020 census, Los Alamos had a population of 13,179, with 5,653 households and 3,522 families. The population density was .
The median age was 39.6 years. 22.8% of residents were under the age of 18, 6.3% were from 18 to 24, 27.5% were from 25 to 44, 26.9% were from 45 to 64, and 16.5% were 65 years of age or older. For every 100 females there were 102.1 males, and for every 100 females age 18 and over there were 102.5 males age 18 and over.
98.3% of residents lived in urban areas, while 1.7% lived in rural areas.
Of the households, 30.6% had children under the age of 18 living in them. Of all households, 50.4% were married-couple households, 22.7% were households with a male householder and no spouse or partner present, and 22.0% were households with a female householder and no spouse or partner present. About 32.4% of all households were made up of individuals and 10.9% had someone living alone who was 65 years of age or older.
There were 6,026 housing units at an average density of , of which 6.2% were vacant. The homeowner vacancy rate was 1.1% and the rental vacancy rate was 4.5%.
Demographic estimates The 2016–2020 5-year American Community Survey estimates show an average household size of 2.2 and an average family size of 2.9. The percent of those with a bachelor's degree or higher was estimated to be 50.6% of the population.
Income and poverty The 2016–2020 5-year American Community Survey estimates show that the median household income was $114,034 (with a margin of error of +/- $9,349) and the median family income was $139,184 (+/- $15,168). Males had a median income of $83,875 (+/- $7,095) versus $57,000 (+/- $11,331) for females. The median income for those above 16 years old was $72,606 (+/- $8,291). Approximately, 3.2% of families and 4.7% of the population were below the poverty line, including 4.2% of those under the age of 18 and 3.6% of those ages 65 or over.
2010 census As of the 2010 United States census, there were 12,019 people with a population density of . The median age is 40 years. Of the people, 24.8% are under the age of 18, 4.8% are ages 18 to 24, 29.2% are ages 25 to 44, 28.2% are ages 45 to 64, and 12.9% are ages 65 years or older. For every 100 females, there were 101.3 males.
Culture Notable people
Manhattan Project Jack Aeby, environmental physicist who took the only well-exposed color photograph of the Trinity nuclear test Harold Agnew, physicist and third director of Los Alamos National Laboratory (1970-1979) Luis Alvarez, nuclear physicist Kenneth Bainbridge, physicist and director of the Trinity nuclear test Robert Bacher, nuclear physicist Hans Bethe, German-American nuclear physicist, awarded 1967 Nobel Prize in Physics Niels Bohr, Danish nuclear physicist, awarded 1922 Nobel Prize in Physics