ZIP 83431 falls in Jefferson County, Idaho, where we hold 6,538 parcels measured as septic county-wide and 2,535 on sewer. We do not have a per-ZIP parcel count for this county, so this is the county total, not a count specific to ZIP 83431.
| County | Land in this ZIP | Documents held | On septic (county) | On sewer (county) |
|---|---|---|---|---|
| Jefferson County, Idaho | 100% | — | 6,538 | 2,535 |
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 hold 6,538 parcels measured as septic for Jefferson County, Idaho as a whole, not broken out by ZIP.
ZIP 83431 falls in Jefferson County, Idaho.