ZIP 81151 falls in Costilla County, Colorado. We have not measured septic data for this county yet. The county page below has what we do know: where records are kept and whether the portal is public.
ZCTA 81151 is not entirely inside one county. Land-area share is from the 2020 Census ZCTA-to-county relationship file.
| County | Land in this ZIP | Documents held | On septic (county) | On sewer (county) |
|---|---|---|---|---|
| Costilla County, Colorado | 57% | — | — | — |
| Conejos County, Colorado | 43% | 24 | — | — |
Land-area overlap is from the 2020 Census Bureau ZCTA5-to-county relationship file, not an estimate of ours. Parcel and document counts are rows we hold, not a survey of every property in the ZIP. Last verified 2026-09-01.
We have not measured septic-versus-sewer status for this county yet.
ZIP 81151 spans 2 counties: Costilla County, Colorado, Conejos County, Colorado.