Population density and land area criteria used for rural area assistance and other programs
In 1999, RCW 82.14.370 was revised to include a rural county definition based on population density. In this legislation, “rural county” was defined as”… a county with a population density less than 100 persons per square mile.” Subsequent legislation expanded the definition to include”… a county smaller than two hundred twenty-five square miles, and a “county with a population density of 100 persons per square mile or greater, with no city with a population greater than 45,000 persons.” Several statutes now use this definition for tax and other assistance programs.
In 2024, Engrossed Substitute House bill 1835 defined frontier one and frontier two designations within the rural county definition for RCW’s 43.160.020, 43.330.010, 82.02.010. A ‘frontier one’ is a county with a population density of 21 persons per square or fewer, a ‘frontier two’ county is a county with a population density of more than 21 persons per square mile but fewer than 50 people per square mile.
| Counties with a population density less than 100 persons per square mile, counties with a population density of 100 persons or more per square mile with no city with a population greater than 45,000, or counties smaller than 225 square miles as of April 1, 2026, by Frontier designation | ||
|---|---|---|
| Rural: Frontier one | Rural: Frontier two | Rural |
| Adams (11.43) | Asotin (36.08) | Cowlitz** (100.69) |
| Columbia (4.52) | Chelan (28.59) | Franklin (85.29) |
| Ferry (3.34) | Clallam (45.58) | Island* (426.91) |
| Garfield (3.24) | Douglas (25.20) | Mason (70.81) |
| Jefferson (18.91) | Grant (40.12) | San Juan* (107.24) |
| Klickitat (12.66) | Grays Harbor (40.89) | Skagit (78.23) |
| Lincoln (4.89) | Kittitas (21.44) | Walla Walla (50.47) |
| Okanogan (8.26) | Lewis (36.02) | Yakima (61.89) |
| Pend Oreille (10.07) | Pacific (25.65) | |
| Skamania (7.33) | Whitman (22.69) | |
| Stevens (19.39) | ||
| Wahkiakum (17.50) | ||
*Included due to a land area under 225 square miles.
**Included due to population density of 100 or more persons per square mile with no city with a population greater than 45,000.