County · code 35045
San Juan CountyNew Mexico
San Juan County is a county in New Mexico with its seat in Aztec, formed in 1887.
- Founded1887
- County seatAztec
- Named forSan Juan River
- Land area5,517 sq mi + 21 sq mi water
- Population121,661 2020 Census
- Parcels mapped44,687 checked 15 October 2026
Where it is
San Juan on the map of New Mexico
New Mexico has 33 counties and county equivalents, each with its own records office. Shapes with a page are links.
History
Formed in 1887 from Rio Arriba County
An old deed may name a county that no longer exists, or a boundary that has since moved.
San Juan County was created by New Mexico Territory on February 24, 1887, from Rio Arriba County. The county was named after the San Juan River. On March 18, 1901, San Juan County lost territory to McKinley County.
- 1887San Juan County created San Juan created by New Mexico Territory from Rio Arriba. · N.M. Terr. Laws 1887, 27th assy., ch. 13/p. 38
- 1901Lost territory San Juan lost to McKinley. · N.M. Terr. Laws 1901, 34th assy., ch. 39/pp. 75-79
Land and parcels
What the maps cover in San Juan
Who publishes each layer, how good it is, and when we last checked.
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Parcels Good enough
Lot lines and tax-map numbers for 44,687 parcels. Drawn for tax purposes: usually within a few feet of a survey, but not a survey.
edited 26 March 2026 · checked 15 October 2026 -
Address points Missing
No public address points layer found for San Juan County yet.
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Buildings Reference
Roof outlines traced from aerial imagery from FEMA Response Geospatial Office with Oak Ridge National Laboratory (ORNL). Good for seeing what is on a lot; not accurate enough to set a fence from.
checked 18 October 2026
- Official
- from the office that keeps the record
- Good enough
- a reliable statewide or national copy
- Fallback
- a guide only; check the official record
- Missing
- nothing public found yet
People and land
San Juan by the Census
Source: US Census Bureau, 2020 Census; US Census Bureau, 2020 Gazetteer Files. Not endorsed or certified by the Census Bureau.
Rules and offices
San Juan County's official site
We have found the county's site but not its offices yet; start there.
County government
- County government
The official website of San Juan County.
See your own lot on these maps
Open San Juan County on Parcel Chart's free map and click your parcel. Save it with a free account; the full record of your place (site map, projects, documents) is Pro, in early access.
Questions
Common questions about San Juan County
- When was San Juan County founded?
- San Juan County was founded in 1887, formed from Rio Arriba County, and named after San Juan River.
- What is the county seat of San Juan County?
- The county seat of San Juan County is Aztec.
- Is there an online parcel map for San Juan County?
- Yes. A public source publishes a parcel map of 44,687 parcels, rated good enough here. You can click any parcel on it in Parcel Chart's free map, no sign-in needed.
- Has San Juan County's boundary or name changed?
- San Juan County was created in 1887 from Rio Arriba County. Since then the Atlas of Historical County Boundaries records 1 later change, chiefly involving McKinley County.
- Is my lot in a flood zone?
- We do not have flood maps for San Juan County yet. Look up the address on FEMA's Flood Map Service Center, which shows the effective flood map for any lot.
Nearby