- Washington State Route 507 (Wikipedia)
State Route 507 (SR 507) is a Washington state highway in Lewis, Thurston and Pierce counties that extends 43.52 miles (70.04 km) from Interstate 5 (I-5) and U.S. Route 12 (US 12) in Centralia to SR 7 in Spanaway. The highway also intersects SR 510 in Yelm and SR 702 in McKenna. The first appearance of the roadway on a map was in 1916 and since, two highways, Secondary State Highway 5H (SSH 5H) and SSH 1N, were established on the current route of SR 507 in 1937 and 1943. They both became SR 507 during the 1964 highway renumbering.