Washington State Route 308

State Route 308
SR 308 is highlighted in red.
Route information
Auxiliary route of SR 3
Maintained by WSDOT
Length	3.42 mi[1] (5.50 km)
Existed	1971[2]–present
Major junctions
West end	SR 3 in Bangor
East end	Naval Undersea Warfare Center in Keyport
Location
Country	United States
State	Washington
Counties	Kitsap
Highway system
State highways in Washington Interstate US State Scenic Pre-1964 1964 renumbering Former
← SR 307 → SR 310

State Route 308 (SR 308) is a 3.42-mile-long (5.50 km) state highway in the U.S. state of Washington, serving the community of Keyport in Kitsap County. The highway travels generally east from an interchange with SR 3 east of Naval Base Kitsap at Bangor to the main entrance of the Naval Undersea Warfare Center in Keyport. SR 308 was codified as the Keyport branch of State Road 21 in 1929 and continued as the Keyport branch of Primary State Highway 21 (PSH 21) in 1937. During the 1964 highway renumbering, the branch became a section of SR 303, which ran from Bremerton to Bangor and had a spur route serving Keyport. SR 308 was established in 1971 along the old route of SR 303 Spur and was extended in 1991 to the SR 3 freeway after SR 303 was re-routed onto a new freeway in Silverdale.