Mosier Twin Tunnels

Page Index

• Rock Catchment Structure
• West Tunnel - Mosier Twin Tunnels
• Mid-Catchment Structure, Between the Tunnels
• Tunnel Cliff Walk
• East Tunnel - Mosier Twin Tunnels

Oregon State Archives: A 1940 Journey Across Oregon

MOSIER TUNNELS, 119.5 m. [West of Hwy. 730 Junction], one 261 feet and the other 60 feet long, often referred to as the Twin Tunnels, penetrate a promontory more than 250 feet above the river. West of this point the contrast between the barren, semi desert contours of eastern Oregon and the lushness of the Pacific Slope becomes apparent.

Robert W. Hadlow, Columbia River Highway Historic District, National Historic Landmark Nomination

The Mosier Twin Tunnels were constructed a mile east of the Wasco County line and completed in 1921. They consist of two bores, in tandem, running 390 feet. They carried visitors from a cliff-faced road on the west to a plateau on the east, overlooking the Columbia River. Features include two windows in the east tunnel, an observation gallery between the tunnels, and a masonry-railed cliff walk. The tunnels were partially wood lined and originally had masonry portals.

By the 1930s, larger vehicles required widening the tunnels. New linings were installed and the portal rings were enlarged and refaced with imitation voussoirs cast in concrete. Highway officials noted early on that continual rockfall made traveling dangerous in CRH section immediately west of the tunnels. In 1953, at the completion of the water-level route between Hood River and Mosier, the Oregon State Highway Engineer ordered the Mosier Twin Tunnels closed permanently and filled with rubble.

"The state highway department abandoned this section in the early 1950s when the water-level route opened... The portion to the Hood River County—Wasco County line became a county road, serving residences and several gravel pits. With closure of this portion of the old road in the mid-1950s, the right-of-way in Wasco County to HMP 73.1, including the Mosier Twin Tunnels (HMP 72) reverted to surrounding private landowners."

"When they [the Mosier Twin Tunnels] were officially closed in 1953, State Highway Engineer Robert H. Baldock said that they, 'should never be reopened because of the danger to people using the road.'"

"In 1954, the OSHD abandoned the highway’s Mosier Twin Tunnel section, with the right-of-way reverting to adjacent landowners. From 1987 onward, the Oregon Department of Transportation (ODOT) has reacquired ownership of this entire section of the CRH from Hood River to Mosier."

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