Columbia County, WA ZIP Codes
3 ZIP codes cover all or part of Columbia County, Washington: 99328, 99361 and 99359. The Census Bureau counts 4,014 residents in the county, with a median household income of $71,810 and a median home value of $271,200. Median household income ranges from $72,756 in 99328 to $91,367 in 99361. Its largest communities include Dayton and Starbuck.
Columbia County (Census county figures)
| Measure | Census figure |
|---|---|
| Residents | 4,014 |
| Households | 1,862 |
| Median household income | $71,810 |
| Median home value | $271,200 |
| Median age | 49.6 |
| Median rent | $985 |
All 3 ZIP codes together
| Measure | Value |
|---|---|
| Residents (sum of ZIP codes) | 5,732 |
| Households (sum of ZIP codes) | 2,582 |
| Median household income, range across ZIP codes | $72,756 (99328) to $91,367 (99361) |
| Household-weighted average of ZIP medians (an approximation, not a true median) | $79,026 |
| Homeowners | 74.0% |
| Households with kids under 18 | 19.5% |
| Moved in the past year | 15.1% |
| Carrier routes in EDDM2GO's route library | 5 routes, 1,640 homes (1 of 3 ZIP codes) |
Top facts
- Highest median household income in Columbia County: 99361 ($91,367)
- Most residents: 99328 (3,646 people)
- Highest homeownership: 99328 (77.4% own their home)
- Most households with kids: 99361 (21.3% of households)
- Most new movers: 99361 (19.1% moved in last year)
- Youngest median age: 99361 (40.9 years)
- Highest median home value: 99361 ($295,900)
Every ZIP code in Columbia County
| ZIP | Mailing city | Residents | Households | Median income | Home value | Homeowners | With kids | New movers | Carrier routes | Mailboxes | Why listed |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 99328 | Dayton | 3,646 | 1,667 | $72,756 | $272,100 | 77.4% | 19.4% | 13.2% | 5 | 1,801 | 100% of its land |
| 99361 | Waitsburg | 1,992 | 847 | $91,367 | $295,900 | 66.2% | 21.3% | 19.1% | — | — | 32% of its land |
| 99359 | Starbuck | 94 | 68 | $61,000 | $135,400 | 86.8% | 0.0% | 4.3% | — | — | 100% of its land |
A ZIP code is listed for Columbia County when at least 10% of its land is in the county, when it holds at least 10% of the county's land, or when the county is its main county. Totals add up whole ZIP codes, including parts that cross the county line; the Census county figures above do not.
Cities and communities
Price a mailing to Columbia County ZIP codes
EDDM guides
Pick carrier routes on the EDDM route map
Frequently asked questions
- What ZIP codes are in Columbia County, WA?
- 99328, 99361 and 99359. Some cross the county line; the table shows each ZIP's share of land in the county.
- What is the population of Columbia County?
- 4,014 residents in 1,862 households (ACS 5-year estimates, 2020–2024).
- What is the median household income in Columbia County?
- $71,810 for the county as a whole. Its ZIP codes range from $72,756 (99328) to $91,367 (99361).
- Which Columbia County ZIP code has the highest median household income?
- 99361, at $91,367, among ZIP codes with at least 1,000 residents.
- How many carrier routes and mailboxes are in Columbia County?
- For the 1 of 3 ZIP codes in EDDM2GO's stored route library: 5 carrier routes reaching 1,640 residential and 160 business mailboxes. The route map loads the rest when you search them.
This product uses the Census Bureau Data API but is not endorsed or certified by the Census Bureau.