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New Mexico · South New Mexico · #299 Most Populous County in the US
Dona Ana County County Government Offices
New Mexico's southern gateway on the Rio Grande - from Las Cruces's New Mexico State University campus and the historic Mesilla plaza where Billy the Kid was sentenced to the Organ Mountains, White Sands National Park, and the US-Mexico border communities of Sunland Park and Santa Teresa. Property tax, courts, public records, and senior services for Doña Ana County residents.
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Dona Ana County County's assessment ratio means effective tax rates are low — but incorrect appraisals still cost money. Ownwell manages the appeal with no upfront cost.
Office: Doña Ana County/City of Las Cruces Office of Emergency Management – 1170 North Solano, Suite O, Las Cruces, NM 88001 | (575) 647-7901 | Cell: (575) 520-4331; Emergency Manager Amanda Bowen, [email protected], [email protected]. Also serves as liaison for an emerging agreement with the City of Sunland Park; maintains the County’s All Hazard Emergency Operations Plan (AHEOP).
Sheriff: Doña Ana County Sheriff’s Office – 845 N. Motel Blvd, Las Cruces, NM 88007 | (575) 525-1911 or (575) 647-7200. Genuinely New Mexico’s second-largest sheriff’s department, covering 3,814 square miles and roughly 223,000 residents, with substations in Anthony, Chaparral, and Hatch.
Notes: For an active emergency, call 911.
Roads & Utilities
ROADS & TRANSPORTATION
Roads: I-10 and I-25 intersect near Las Cruces, the county seat and New Mexico’s second-most populous city.
Notes: Doña Ana County is New Mexico’s border county with Texas (El Paso County) and Mexico (Chihuahua). Las Cruces, founded 1849 and incorporated 1907, is nicknamed “The City of the Crosses.”
Business & Permits
BUILDING & PERMITS
Office: Doña Ana County Building Permits – confirm current contact via donaana.gov.
Notes: Doña Ana County is genuinely home to New Mexico State University (NMSU), founded 1888 as the state’s oldest public higher education institution and original land-grant university, with roughly 22,700 students system-wide. The county is a leading national producer of chile peppers, onions, and pecans, centered on the historic Mesilla Valley. It also contains the Organ Mountains-Desert Peaks National Monument and portions of White Sands Missile Range and White Sands National Monument – the county’s history is deeply intertwined with the U.S. Army’s border-era forts.
Veterans Services
VETERANS SERVICES
Office: Doña Ana County Veterans Service – confirm current contact via donaana.gov.
Federal: El Paso VA Health Care System (nearby, Texas) or Albuquerque VA Medical Center.
Libraries
LIBRARIES
Confirm current library address/hours via donaana.gov or las-cruces.org (Thomas Branigan Memorial Library serves Las Cruces).
Parks & Recreation
PARKS & RECREATION
Key Assets: Organ Mountains-Desert Peaks National Monument, the historic Town of Mesilla, White Sands National Monument (nearby), and New Mexico State University’s campus are the county’s premier attractions.
Notes: The genuine agricultural distinction (leading chile pepper, onion, and pecan producer) and NMSU’s status as New Mexico’s oldest public university are distinctive local facts.
GIS & Maps
GIS & MAPS
Appraisal/Parcel Search: Doña Ana County Assessor – confirm current contact via donaana.gov.
Animal Services
ANIMAL SERVICES
Animal Service Center of the Mesilla Valley (ASCMV) – the only open-admission municipal shelter serving Las Cruces and unincorporated Doña Ana County (established via a 2008 Joint Powers Agreement between the city and county); received nearly 9,000 animals in 2025; offers microchipping and city/county pet licenses.
APA Las Cruces (nonprofit rescue) – Adoption and Education Center, 537 N. Solano Dr., Las Cruces, NM | Info line (575) 644-0505 | Adoption center (575) 571-4654 | [email protected] | Hours: Tue/Thu/Sat 11 AM-4 PM.
Environmental & Waste
ENVIRONMENTAL / WASTE MANAGEMENT
Office: Doña Ana County Public Works – confirm current contact via donaana.gov.
NOTES: Doña Ana County is the eighth county in the New Mexico v3 A+ sourced redo’s second batch (Doña Ana, Eddy, Grant, Guadalupe, Harding, Hidalgo, Lea). The genuine agricultural leadership (chile, onions, pecans) and NMSU’s status as the state’s oldest public university are distinctive local facts. All contact information above was sourced via web search as of early August 2026 and should be reconfirmed directly with the relevant office before a visit, deadline-sensitive filing, or emergency-adjacent decision.
About Dona Ana County County
Doña Ana County is New Mexico’s second most populous county and the 299th most populous in the United States, covering 3,807 square miles of the Rio Grande valley and the Chihuahuan Desert in southern New Mexico along the Texas and Mexico borders.
Las Cruces (population ~111,000, the county seat) is New Mexico’s second largest city – a rapidly growing city in the Rio Grande valley with an economy anchored by New Mexico State University (NMSU) (enrollment ~14,000), White Sands Missile Range (the Army’s primary missile testing facility, covering 3,200 square miles in Doña Ana and adjacent counties), and healthcare. Las Cruces is surrounded by extraordinary landscapes – the Organ Mountains rise dramatically to the east (now part of the Organ Mountains-Desert Peaks National Monument), the Rio Grande flows through the agricultural bosque to the west, and White Sands National Park is approximately 50 miles northeast.
Historic Mesilla (La Mesilla) is a small village adjacent to Las Cruces with extraordinary historical significance – the Mesilla Plaza was where Billy the Kid (William Bonney) was tried and convicted of murder in 1881. The Double Eagle Restaurant (in a historic building on the plaza) and the surrounding adobe architecture preserve the 19th-century character of this important border community. Mesilla was also briefly the capital of the Confederate Arizona Territory during the Civil War.
White Sands National Park – 275 square miles of gypsum sand dunes rising up to 60 feet, the world’s largest gypsum dune field – is one of New Mexico’s most extraordinary landscapes. The dunes’ stark white contrast against the blue sky and Organ Mountains creates an otherworldly visual environment.
Sunland Park and Santa Teresa anchor the county’s international border communities adjacent to El Paso, Texas and Ciudad Juárez, Mexico – the Santa Teresa Port of Entry handles significant commercial cross-border traffic.
Doña Ana County’s population is approximately 70% Hispanic – reflecting the region’s deep Spanish colonial, Mexican, and New Mexican cultural heritage that predates American statehood by centuries.
All Services
Browse every category and topic available for this county.
New Mexico assesses residential property at 33.33% (one-third) of market value, with a 3% annual cap on taxable value increases for established owners (similar in effect to California’s Prop 13 and Colorado’s approach). The Doña Ana County Assessor at 845 N. Motel Boulevard, Las Cruces, NM 88007, phone 575-647-7400, determines market values.
The appeal process: File a protest with the Doña Ana County Assessor within 30 days of receiving your Notice of Value. If dissatisfied, appeal to the County Valuation Protests Board, then to District Court.
New Mexico has no estate tax and no inheritance tax. Assets pass subject only to federal estate tax above $13.61 million (2025).
OWNWELL CTA: Doña Ana County Assessor protest: within 30 days of Notice of Value. Las Cruces NMSU and missile range employment driving consistent appreciation. 3% annual taxable value cap protects established owners. No NM estate or inheritance tax. Ownwell manages the appeal with no upfront cost.
Recommended
Doña Ana County Assessor protest: within 30 days of Notice of Value. Las Cruces NMSU and missile range employment driving consistent appreciation. 3% annual taxable value cap protects established owners. No NM estate or inheritance tax. Ownwell manages the appeal with no upfront cost.
Courts & Legal
Courts & Legal
District Court (Probate): The Doña Ana County District Court – 3rd Judicial District at 201 W. Picacho Avenue, Las Cruces, NM 88005, phone 575-523-8200, handles probate, estate administration, guardianships, and all civil and criminal matters.
County Clerk: The Doña Ana County Clerk at 845 N. Motel Boulevard, Las Cruces, phone 575-647-7421, maintains all real property records and vital records. Land records searchable online.
Senior Services
The Doña Ana County Senior Programs and the Area Agency on Aging – Region VI serve the county’s senior population. Contact Doña Ana County Health and Human Services at 575-647-7200. Memorial Medical Center (University of New Mexico Health System) provides significant geriatric care as the county’s primary hospital.
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Marriage & Vital Records
Marriage licenses, divorce records, and birth & death certificates are handled by the following office(s):
COUNTY CLERK
845 N. Motel Blvd., Las Cruces, NM 88007
(575) 647-7421
COUNTY CLERK — ELECTIONS
845 N. Motel Blvd., Las Cruces, NM 88007
(575) 647-7421
Genealogy
PRIMARY STATEWIDE RESEARCH CENTERS (same across all New Mexico counties)
New Mexico State Records Center and Archives, 1205 Camino Carlos Rey, Santa Fe, NM 87507.
New Mexico Genealogical Society, P.O. Box 8283, Albuquerque, NM 87198.
County-level record sources
Doña Ana County Probate Court, Las Cruces (probate case files – see Probate section above).
New Mexico State University, in Las Cruces, holds significant regional archival collections.
Local societies
No dedicated Doña Ana County genealogical society was confirmed in available directories.
Probate & Estate
Losing someone and having to deal with courts and paperwork at the same time is hard. This section won’t make that easier, but it should tell you what to expect, what it costs, and where to go – so at least you’re not walking in blind.
Where to go
Doña Ana County Probate Court 845 North Motel Boulevard, Las Cruces, NM 88007 (575) 525-6132
Doña Ana County is in southern New Mexico, New Mexico’s second most populous county, seated in Las Cruces.
Step 1: figure out which path applies
New Mexico adopted the Uniform Probate Code. New Mexico has a dual court system: the county PROBATE COURT handles informal, uncontested probate matters with minimal court involvement, and has concurrent jurisdiction with the DISTRICT COURT over informal proceedings. The District Court alone handles formal probate – contested cases, determinations of heirship, and trust matters.
Small Estate Affidavit / Affidavit of Successor in Interest (N.M. Stat. § 45-3-1201) – available when the value of the entire estate (after liens and encumbrances) does not exceed $50,000 and does NOT include any real property. At least 30 days must have passed since death. This skips probate court entirely – the affidavit is presented directly to banks, the DMV, or other institutions holding the property.
Homestead Transfer Affidavit for Surviving Spouse (N.M. Stat. § 45-3-1205) – available 6 months after death, when the surviving spouse and decedent owned a homestead as community property valued at $500,000 or less (for property tax purposes). The affidavit is recorded with the county clerk and can avoid formal probate for the residence, but only if funeral expenses, expenses of last illness, and all unsecured debts have already been paid.
Informal Probate – the most common path for uncontested estates, filed with either the Probate Court or the District Court in the county where the decedent was domiciled. No hearing required.
Formal Probate – required for contested cases, disputes over heirship, or trust matters. Only the District Court can hear these.
Step 2: filing for informal or formal probate
File a petition with the Probate Court or District Court in the county where the decedent was domiciled. A probate may be started up to 3 years after death.
The court appoints the personal representative and issues Letters Testamentary or Letters of Administration.
The personal representative notifies creditors; New Mexico’s creditor claim period is 2 months from notice to creditors – one of the shortest in the country.
The personal representative inventories the estate’s assets, pays debts and expenses, and distributes the remaining assets according to the will or New Mexico’s intestacy statute.
The estate is closed, typically within 6 to 12 months for straightforward, uncontested cases.
What it costs
The filing fee for probate in Probate Court is generally around $30 – notably lower than in most states. District Court filing fees run higher, commonly $100–$232 depending on the county and complexity.
New Mexico does not set a fixed statutory percentage for personal representative compensation; courts typically look to a reasonable guideline of about 2–4% of the estate’s value.
New Mexico has no state estate tax and no state inheritance tax. Only the federal estate tax could apply, and only to very large estates.
Probate filings, estate administration, and guardianship matters are handled by the following office(s):
Public Safety & Arrests
Arrest records, inmate search, and law enforcement services are handled by the following office(s):
SHERIFF
845 N. Motel Blvd., Las Cruces, NM 88007
(575) 647-7000
Elections & Voting
Voter registration, polling locations, and elections information are handled by the following office(s):
COUNTY CLERK — ELECTIONS
845 N. Motel Blvd., Las Cruces, NM 88007
(575) 647-7421
ELECTIONS
845 N. Motel Blvd., Las Cruces, NM 88007
(575) 647-7421
Health & Human Services
Offices & Contacts
Health services, social services, and assistance programs are handled by the following office(s):
Office: Doña Ana County Public Health – confirm current contact via donaana.gov.
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