San Juan County
New Mexico · County seat: Aztec · Active county or equivalent
FIPS code 35045 is San Juan County, New Mexico. With a population of 121,798 (2022 ACS estimate), it ranks #5 in New Mexico and #518 nationally. San Juan County is part of the Farmington, NM. The state FIPS code for New Mexico is 35. This code is used in Census Bureau, BLS, EPA, HUD, and USDA federal datasets to identify this county.
County FIPS
35045
Population
121,798
2022 ACS · #518 nationally
Density
22.1/mi²
people per sq mile
Land Area
5,513
sq miles
Urban/Rural
Metro — under 250K population
RUCC 3
How This FIPS Code Works
The 5-digit FIPS code 35045 is formed by combining the 2-digit state identifier 35 (New Mexico) with the 3-digit county identifier 045. Together they uniquely identify San Juan County in every US federal dataset. No two counties share the same 5-digit FIPS code.
Census ACS Data for FIPS 35045
From the 2022 ACS 5-year estimates — the same values you'd retrieve by querying the Census API with county FIPS 35045.
Median Household Income
$50,734
ACS B19013_001E
Poverty Rate
24.5%
ACS B17001 (below poverty level)
Median Age
36.8
ACS B01002_001E
Metropolitan Area
Adjacent Counties (8)
Counties that share a border with San Juan County. Useful for regional analysis — these are the geographies you'd typically include when studying labor markets, commuting zones, or environmental spillovers around FIPS 35045.
Federal Datasets Using Code 35045
FIPS code 35045 appears as the county identifier in the following federal datasets. Analysts joining data across these sources use this code as the common geographic key.
Using FIPS Code 35045 in Code
Common patterns for querying federal datasets by this county's FIPS code. The leading zeros are significant — always treat FIPS codes as strings, not integers.
import requests
url = "https://api.census.gov/data/2022/acs/acs5"
params = {
"get": "NAME,B19013_001E,B01003_001E",
"for": "county:045",
"in": "state:35",
"key": "YOUR_CENSUS_API_KEY",
}
r = requests.get(url, params=params)
data = r.json() # [[header...], [San Juan County, New Mexico, income, pop, ...]
-- 5-digit combined FIPS (state + county)
SELECT * FROM your_table WHERE county_fips = '35045';
-- Some datasets store state and county separately
SELECT * FROM your_table
WHERE state_fips = '35'
AND county_fips = '045';
-- ⚠ Never cast to integer — leading zeros are lost:
-- county_fips = 35045 is WRONG for this county
library(tidycensus)
get_acs(
geography = "county",
variables = c(income = "B19013_001E", pop = "B01003_001E"),
state = "35",
county = "045",
year = 2022
)
ZIP Codes in San Juan County
ZIP codes do not align perfectly with county boundaries — a single ZIP code can span multiple counties, and a county can contain parts of many ZIP codes. The ratios below (from the Census 2020 ZCTA relationship file) show the land area share of each ZCTA that falls within San Juan County. Why FIPS ≠ ZIP →
| ZIP Code | % in county |
|---|---|
| 87499 | 100.0% |
| 87415 | 100.0% |
| 87416 | 100.0% |
| 87417 | 100.0% |
| 87418 | 100.0% |
| 87420 | 100.0% |
| 87421 | 100.0% |
| 87455 | 100.0% |
| 87461 | 100.0% |
| 87364 | 100.0% |
| 87401 | 100.0% |
| 87402 | 100.0% |
| 87410 | 100.0% |
| 87413 | 100.0% |
| 87037 | 96.7% |
| 87419 | 53.8% |
| 87325 | 38.5% |
| 87328 | 29.7% |
| 87412 | 27.8% |
| 81137 | 17.3% |
| 87313 | 11.1% |
| 86514 | 1.0% |