New Mexico county map

How New Mexico’s counties are laid out

New Mexico’s 33 counties cover 121,590 square miles, the fifth-largest state, so the average county is about 3,700 square miles. The 2,117,522 people counted in 2020 are strongly concentrated along the Rio Grande: Bernalillo, Sandoval, Valencia, Santa Fe and Doña Ana counties, all on the river, hold about 60 per cent of the state. Away from the river the counties are large blocks of ranch land, oil country and national forest with seats of a few thousand people.

The oldest counties are older than the territory. Spanish and then Mexican governments administered the province in districts centred on Santa Fe, Albuquerque and Santa Cruz de la Cañada, and when the first territorial legislature met in 1852 it confirmed nine counties: Bernalillo, Doña Ana, Rio Arriba, San Miguel, Santa Ana, Santa Fe, Socorro, Taos and Valencia. Santa Ana was merged into Bernalillo in 1876; the other eight are still on the map, which is why several New Mexico counties have Spanish saints’ names and irregular boundaries following old land grants. The eastern plains counties — Curry, Roosevelt, Quay, Union, Lea, De Baca, Harding — date from the homestead years between 1903 and 1921.

Two counties are unusual. Los Alamos County was created in 1949 around the wartime laboratory and is a consolidated city-county of only about 109 square miles. Cibola County, split from Valencia in 1981, is the newest county in the state and one of the newest in the US. The whole state is on Mountain Time.

All 33 counties of New Mexico

Five county facts

• Largest by area: Catron County, seat Reserve, about 6,930 square miles on the Arizona line in the Gila country, almost all of it national forest and wilderness. Socorro, Otero, Cibola, San Juan and Lincoln counties are each over 4,800 square miles.
• Smallest by area: Los Alamos County, about 109 square miles on the Pajarito Plateau north-west of Santa Fe, the only county in the state under 1,000 square miles. Bernalillo County, at about 1,170 square miles, is the next smallest.
• Most populous: Bernalillo County, seat Albuquerque, with about 676,000 people in 2020 — 32 per cent of the state. Doña Ana County (Las Cruces), with about 220,000, is second; Santa Fe and Sandoval counties are each around 150,000.
• Least populous: Harding County, seat Mosquero, with about 660 people on the north-eastern plains — it has lost residents in every census since it was created in 1921. De Baca (Fort Sumner) and Catron counties are the only others under 4,000.
• Oldest and newest: Bernalillo, Doña Ana, Rio Arriba, San Miguel, Santa Fe, Socorro, Taos and Valencia (1852) are the oldest. Cibola County (1981) is the newest. Los Alamos is the state’s only consolidated city-county; there are no independent cities.

Reading the map

Press Streets and zoom in on the highlighted state to see county lines. The Rio Grande enters from Colorado through Taos and Rio Arriba counties, passes Santa Fe County, Albuquerque and Valencia and Socorro counties, and crosses Sierra and Doña Ana counties to El Paso. The Continental Divide runs through San Juan, McKinley, Cibola, Catron, Grant and Hidalgo counties in the west. San Juan County holds the state’s share of the Four Corners and the Colorado Plateau; Lea and Eddy counties in the south-east are the Permian Basin oil fields and Carlsbad Caverns. Hidalgo County’s “bootheel” is the southernmost point on the Mexican border. Curry, Roosevelt and Quay counties on the Texas line are the flat Llano Estacado.

Related maps

• New Mexico map — cities, borders and geography.
• Blank New Mexico map and printable New Mexico map.
• Santa Fe, the state capital; Albuquerque, the largest city, in Bernalillo County.
• Neighbouring county maps: Colorado, Oklahoma, Texas, Arizona, Utah.
• Mountain division · the West · Southwest region · Mountain Time Zone.
• Geography: Rio Grande, Four Corners, Rocky Mountains, US deserts.
• All US county maps.