The Oregon State Highway Commission added the Willamette Highway No. 18, from Goshen via Oakridge to Crescent, to the state highway system on November 24, 1922. The road was entirely unimproved when it was taken over, and improvement progressed slowly from the Goshen end. The roadway received the signed Oregon Route 58 designation in 1932, when the Oregon Route system was first laid out. A major realignment, crossing the Cascades at Willamette Pass rather than Emigrant Pass, was designed in 1933, and incorporated a number of half viaducts built into the hillside and one tunnel (the Salt Creek Tunnel) in order not to scar the hillsides more than is absolutely necessary through the Willamette National Forest. An opening ceremony for the highway, thought at the time to be the last major highway that the state would build, was held on July 30, 1940. The road remained partially oiled gravel until the mid-1960s.