New Mexico County records vary widely from county to county in both quality and quantity. Some have been carefully preserved while others have been much abused and neglected. Some New Mexico records have simply disappeared. For genealogists doing research in New Mexico there is no effective replace for an on-site search of county courthouse records. For Definitions of all court terms see the Genealogy Encyclopedia.

New Mexico is divided into 33 counties. There were originally nine counties formed in 1852. Santa Ana County, New Mexico Territory, one of the nine original counties, was annexed in 1876 to Bernalillo County, New Mexico. New Mexico State Government is located in Santa Fe.

New Mexico Counties

The county seat’s county clerk’s office retains some probate records, as well as plats, surveys, mining records, deeds, land records, and records pertaining to marriages. They also have files containing mortgages, liens, powers of attorney, military discharges and other documents and affidavits. The district clerk’s office holds records pertaining to probate matters.

The New Mexico State Records Center and Archives has records on file that predate formal county organizations and certain counties may also have similar records on file from Mexican and Territorial times.

The links in the table below link to county and city government offices and is limited to government-maintained websites. If you know of a New Mexico county that has an official government web site but is not linked, or if the link is in error, please contact us so we may edit our database.

County Date Formed Parent County County Seat
Bernalillo January 6, 1852 One of the nine original counties. Albuquerque
Catron February 25, 1921 Part of Socorro County. Reserve
Chaves February 25, 1889 Part of Lincoln County. Roswell
Cibola June 19, 1981 Part of Valencia County. Grants
Colfax January 25, 1869 Part of Mora County. Raton
Curry February 25, 1909 Parts of Quay and Roosevelt Counties. Clovis
De Baca February 28, 1917 Parts of Chaves and Guadalupe Counties. Fort Sumner
Dona Ana January 6, 1852 One of the nine original counties. Las Cruces
Eddy February 25, 1889 Part of Lincoln County. Carlsbad
Grant January 30, 1868 Part of Doña Ana County. Silver City
Guadalupe February 26, 1891 Part of San Miguel County. Santa Rosa
Harding March 4, 1921 Parts of Mora and Union Counties. Mosquero
Hidalgo February 25, 1919 Part of Grant County. Lordsburg
Lea March 7, 1917 Parts of Chaves and Eddy Counties. Lovington
Lincoln January 16, 1869 Part of Socorro County. Carrizozo
Los Alamos March 16, 1949 Parts of Sandoval and Santa Fe Counties. Los Alamos
Luna March 16, 1901 Parts of Doña Ana and Grant Counties. Deming
McKinley February 23, 1899 Part of Bernalillo County. Gallup
Mora February 1, 1860 Part of Taos County. Mora
Otero January 30, 1899 Parts of Doña Ana and Lincoln Counties. Alamogordo
Quay February 28, 1903 Part of Guadalupe County. Tucumcari
Rio Arriba January 6, 1852 One of the nine original counties. Tierra Amarilla
Roosevelt February 28, 1903 Parts of Chaves and Guadalupe Counties. Portales
San Juan February 24, 1887 Part of Bernalillo County. Aztec
San Miguel January 6, 1852 Part of Rio Arriba County. Las Vegas
Sandoval March 10, 1903 One of the nine original counties. Bernalillo
Santa Fe January 6, 1852 One of the nine original counties. Santa Fe
Sierra April 3, 1884 Parts of Doña Ana and Socorro Counties. Truth or Consequences
Socorro January 6, 1852 One of the nine original counties. Socorro
Taos January 6, 1852 One of the nine original counties. Taos
Torrance March 16, 1903 Parts of Bernalillo and Valencia Counties. Estancia
Union February 23, 1893 Parts of Colfax, Mora and San Miguel Counties. Clayton
Valencia January 6, 1852 One of the nine original counties. Los Lunas

Interactive Map of New Mexico Counties Formation

(New Mexico maps made with the use AniMap Plus 3.0 & with the Permission of the Goldbug Company)

New Mexico Extinct Counties

New Mexico has counties that no longer exist. They were established by the state, provincial, or territorial government. Most of these counties were created and disbanded in the 19th century; county boundaries have changed little since 1900 in the vast majority of states. These counties need to be looked at when doing genealogy research. Pay close attention where the courthouse records went to if the county was abolished or combined with another county.

  • Santa Ana County [1852 Map]was one of the seven original partidos created in New Mexico under Mexican rule (was in Judicial District No. 1 from 1847 to 1863, then in JD 2 until 1876). Under U.S. rule, it became a U.S. Territorial county from 1852 until 1876, when it was absorbed by Bernalillo County.

New Mexico Counties with Burned Courthouses

The damage to courthouses greatly has a bearing on genealogists in every way. No only are these historic structures torn from our lifetimes, so are the records they housed: marriage, wills, probate, land records, and others. Once destroyed they’re lost forever. Although they have been placed on mircofilm, computers and film burn too. The most heartbreaking side of this is the reason that nearly all of our courthouses are destroyed at the hands of arsonist. Although, not all records were lost. Many New Mexico counties have suffered a loss of records due to
courthouse fires, floods, and theft.

  • Sandoval County Courthouse had a Record loss in 1926.