Cowlitz County Flag

Cowlitz County

State:
Washington
County Seat:
Kelso

Cowlitz County's estimated 2026 population is 116,006 with a growth rate of 0.98% in the past year according to the most recent United States census data. Cowlitz County is the 12th largest county in Washington. The 2010 population was 102,358 and has seen a growth of 13.33% since that time.

116,006
Total Population
102
Population Density (mi²)
12
Population Rank (State)
1.1K 0.98%
Annual Population Growth

Cowlitz County Population

Demographics

Economics and Income Statistics