High Quality Content by WIKIPEDIA articles! State Route 123 (SR 123) is a state highway in the Gifford Pinchot National Forest and Mount Rainier National Park east of Mount Rainier in the U.S. state of Washington. Located in the counties of Lewis and Pierce, the 16.34-mile (26.30 km) long roadway extends through a heavily forested canyon from U.S. Route 12 (US 12) to SR 410. First established as a branch of State Road 5 in 1923, the designation of SR 123 has changed from a branch of Primary State Highway 5 (PSH 5) in 1937 to SR 143 during the 1964 highway renumbering and SR 123 in 1967. The northern terminus of the highway, Cayuse Pass, is closed annually and in late 2006, the Hanukkah Eve Wind Storm of 2006 washed out a 10.90-mile (17.54 km) long segment of the roadway.