ZIP code 99111
Where is ZIP code 99111?
Colfax, Washington
Whitman County · Standard ZIP code
ZIP code 99111 belongs to Colfax, Washington in Whitman County. 99111 is a standard ZIP code, so it covers street addresses as well as PO Boxes. It is in the Pacific Time zone and uses area code 509. About 4,038 people live in the 99111 area, where the median household income is $73,393. The closest ZIP codes are 99102 (Albion, 8.2 mi southeast), 99174 (Steptoe, 8.7 mi north) and 99130 (Garfield, 12.9 mi northeast).
| ZIP code | 99111 |
|---|---|
| Type | Standard ZIP code for street addresses and PO Boxes |
| Status | Active |
| City | Colfax |
| Also accepted | Diamond |
| State | Washington (WA) |
| County | Whitman County |
| Time zone | Pacific Time · now |
| Area code | 509 |
| Coordinates | 46.88, -117.367 map |
| 3-digit prefix | 991 |
Population and income in 99111
| Population | 4,038 · lower than 53% of Washington ZIP codes |
|---|---|
| People per square mile | 13 · lower than 77% of Washington ZIP codes |
| Median age | 41.8 years · higher than 55% of Washington ZIP codes |
| Men / women | 48% / 53% |
| Median household income | $73,393 · lower than 66% of Washington ZIP codes |
| Income per person | $37,809 |
| Below the poverty line | 10% |
| Bachelor’s degree or higher | 31% of adults 25+ |
| Median home value | $295,800 · lower than 80% of Washington ZIP codes |
| Median rent | $953 a month |
| Housing units | 1,932 |
| Households | 1,714 (2.32 people on average) |
| Owners / renters | 73% / 27% |
| Land area | 306.99 sq mi (plus 0.1 sq mi of water) |
Source: U.S. Census Bureau, American Community Survey 5-year estimates (2020–2024) for ZIP Code Tabulation Area 99111. Census ZIP areas are close to, but not exactly the same as, USPS delivery areas.
ZIP codes near 99111
| ZIP code | City | Distance | Type |
|---|---|---|---|
| 99102 | Albion, WA | 8.2 mi SE | PO Box only |
| 99174 | Steptoe, WA | 8.7 mi N | PO Box only |
| 99130 | Garfield, WA | 12.9 mi NE | Standard |
| 99161 | Palouse, WA | 13.4 mi E | Standard |
| 99164 | Pullman, WA | 13.6 mi SE | Unique |
| 99163 | Pullman, WA | 13.6 mi SE | Standard |
| 99104 | Belmont, WA | 16.4 mi NE | Standard |
| 99171 | Saint John, WA | 16.6 mi NW | Standard |
| 99176 | Thornton, WA | 17 mi N | Standard |
| 99125 | Endicott, WA | 17.3 mi W | Standard |
| 99158 | Oakesdale, WA | 18.1 mi N | Standard |
| 83872 | Viola, ID | 18.7 mi E | Standard |
Straight-line distance between ZIP code center points. Find every ZIP code within 10 miles of 99111 or measure the distance to another ZIP code.
How to address mail to 99111
123 MAIN ST
COLFAX WA 99111
Put the city, the two-letter state code and the ZIP code on the last line. USPS also accepts DIAMOND as the city name for 99111. Adding the 4-digit ZIP+4 code (99111-XXXX) helps mail sort faster but isn’t required.
Questions
- What city is ZIP code 99111?
- 99111 is a Colfax, Washington ZIP code. Diamond is also accepted as the city name.
- What county is 99111 in?
- ZIP code 99111 is in Whitman County, Washington.
- What time zone is ZIP code 99111 in?
- 99111 is in the Pacific Time zone (America/Los_Angeles).
- What area code is 99111?
- Phone numbers in ZIP code 99111 use area code 509.
- What is the population of ZIP code 99111?
- About 4,038 people live in ZIP code 99111, according to the Census Bureau’s American Community Survey (2020–2024).
- What is the median income in 99111?
- The median household income in 99111 is $73,393 a year, lower than 66% of Washington ZIP codes.
- What ZIP codes are near 99111?
- The nearest ZIP codes to 99111 are 99102 (Albion, 8.2 miles), 99174 (Steptoe, 8.7 miles), 99130 (Garfield, 12.9 miles) and 99161 (Palouse, 13.4 miles).