ZIP 99401 falls in Asotin County, Washington, where we hold 3,524 parcels measured as septic county-wide and 5,048 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 99401.
| County | Land in this ZIP | Documents held | On septic (county) | On sewer (county) |
|---|---|---|---|---|
| Asotin County, Washington | 100% | 54 | 3,524 | 5,048 |
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 3,524 parcels measured as septic for Asotin County, Washington as a whole, not broken out by ZIP.
ZIP 99401 falls in Asotin County, Washington.