Secondary State Highway 8D

SSH 8D was added to the state highway system in 1937. This route began at Jct PSH 8 (US 830) in Bingen and headed northerly via White Salmon to Trout Lake, then westerly, ending at the Columbia National Forest boundary. In 1951, a western branch or spur was added, starting at Jct PSH 8 (US 830) a short distance east of the US 830 White Salmon River bridge and heading north along the east bank of the White Salmon River to a junction with the SSH 8D trunk a few miles north. When the current state highway numbering system was first posted in January 1964, SSH 8D became signed as SR 121.