Where is the Knowles Creek Tunnel?

August 11, 2025

Adventure

The history of the route that would become Oregon Route 126 (OR 126) dates back to when the route between Florence and Ontario was designated as US 28. The original route of US 28 from Florence to Eugene ran through Junction City and overlapped US 99 from there south to Eugene. In 1937, US 28 was truncated and its western terminus moved to Glenwood. On February 1, 1952, US 28 was eliminated from the United States Numbered Highway System and the section between Prineville and Eugene was then designated U.S. Route 126.

Knowles Creek Tunnel Construction

The construction of the tunnel on Highway 126 between Mapleton and Walton, Oregon, is specifically tied to the Knowles Creek tunnel, which was opened to traffic on June 4, 1957. This tunnel was part of the long-awaited direct route between Eugene and the coast, known as “Route F,” which was completed in 1957. The construction of this route was primarily funded by the Lane County government with assistance from the federal government, with the goal of bypassing the longer Stagecoach Road, which was proposed as early as the 1930s. The Knowles Creek tunnel was later renamed the Petersen Tunnel for Ralph A. Petersen, a Lane County commissioner who had lobbied for the highway’s construction.

Renaming and Redesignation

The state of Oregon formally named the new route the Eugene-Mapleton Highway, but it was not assigned a route number until 1964, when it became OR 126. In 1972, the American Association of State Highway Officials dropped US 126 from its highway system, and the state of Oregon promptly redesignated the Prineville-Eugene section of the former U.S. Route, and the Mapleton-Florence section of OR 36, as OR 126.

Additional Context

The original route of US 28 west of Brickerville is no longer on the state highway system. The place where OR 126 and its predecessors cross the Cascades has changed over the years, with the original highway routed over McKenzie Pass, which was frequently closed in winter. In 1962, the Clear Lake Cutoff was constructed, and US 126 was re-routed over the cutoff, running concurrently with US 20 east over the Cascades to Sisters.

During the 1930s, the Stagecoach Road and the Wildcat Creek Covered Bridge were bypassed by the tunnel and the Mapleton Bridge when modern OR 126 was built. The Wildcat Creek Covered Bridge, built in 1925, still exists just off of OR 126 and is a point of interest for passive exploration.