Cowlitz County, Washington

Cowlitz County profile, demographic data, and geographic information.

Local Government & Public Administration

Authoritative general-purpose local government units serving this area U.S. Census Bureau GUS (2026) / GMAF

Government Unit	Unit Type	Jurisdiction Role	Contact / Address
COUNTY OF COWLITZ GUS Population: 113,982 (2024) ID: 176794	County	Official County Government	Contact: BOARD OF COWLITZ COUNTY COMMISSIONER 207 N 4TH AVE, RM 305, KELSO WA 98626-4191
CITY OF LONGVIEW GUS Population: 38,294 (2024) ID: 114615	Municipal	Municipal Government Within County	Contact: FINANCE DIRECTOR PO BOX 128, LONGVIEW WA 98632-7080
CITY OF KELSO GUS Population: 12,737 (2024) ID: 194183	Municipal	Municipal Government Within County	Contact: MAYOR PO BOX 819, KELSO WA 98626-0078
CITY OF WOODLAND GUS Population: 6,496 (2024) ID: 205585	Municipal	Municipal Government Within County	Contact: CLERK/TREASURER PO BOX 9, WOODLAND WA 98674-0100
CITY OF KALAMA GUS Population: 3,131 (2024) ID: 176819	Municipal	Municipal Government Within County	Contact: CLERK/TREASURER PO BOX 1007, KALAMA WA 98625-0900
CITY OF CASTLE ROCK GUS Population: 2,445 (2024) ID: 136105	Municipal	Municipal Government Within County	Contact: CLERK/TREASURER PO BOX 370, CASTLE ROCK WA 98611-0370