ZIP codes in Alamosa County
6 ZIPs touch Alamosa County, Colorado. The blue dashed line is the county border; orange ZIPs reach into it.
6
ZIP codes
4
cross the county line
26,397
people in these ZIPs
64
counties in CO
Most people
Alamosa County ZIP list
More counties in Colorado
- Adams County44
- Arapahoe County41
- Archuleta County6
- Baca County8
- Bent County7
- Boulder County30
- Broomfield County7
Questions people actually ask
How many ZIP codes are in Alamosa County, Colorado?
6 ZIP codes reach into Alamosa County, including 1 PO Box or single-address ZIPs placed by the town they serve. 4 of them are only partly in the county and also cover a neighboring county.
Which ZIP code in Alamosa County has the most people?
81101 (Alamosa) has about 15,550 residents, the most of any ZIP touching Alamosa County, in the Census Bureau’s ACS 2020–2024 estimates.
Can a ZIP code be in Alamosa County and another county?
Yes. ZIP codes follow mail routes, not county lines. Rows marked with a percentage show how much of that ZIP’s land is in Alamosa County. For one address, pin the exact spot on the ZIP finder to see its county.
Where does this list come from?
ZIP areas and their county overlaps come from the Census Bureau’s 2020 ZIP Code Tabulation Area to county relationship file. PO Box ZIPs have no area, so each is placed in the county of the ZIP area nearest the town it serves.
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Updated 2026-11-10 · Where the data comes from