ZIP 99116 falls in Okanogan County, Washington, where we hold 14,350 parcels measured as septic county-wide and 6,203 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 99116.
ZCTA 99116 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) |
|---|---|---|---|---|
| Okanogan County, Washington | 98% | 5 | 14,350 | 6,203 |
| Grant County, Washington | 2% | 15,176 | 14,575 | 16,431 |
| Douglas County, Washington | 0% | 63 | 5,222 | 8,831 |
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 14,350 parcels measured as septic for Okanogan County, Washington as a whole, not broken out by ZIP.
ZIP 99116 spans 3 counties: Okanogan County, Washington, Grant County, Washington, Douglas County, Washington.