Construction to Complete the Historic Columbia River State Trail Will Cause Closures on I-84 This Month

Contractors are set to begin rock blasting to form Mitchell Point Tunnel.

The Historic Columbia River Highway State Trail will be one step closer to completion later this month, but work on one of the route’s most striking features will cause some holdups for travelers on Interstate 84.

Beginning Thursday, Oct. 7, drivers headed between Cascade Locks and Memaloose State Park east of Mosier should plan for long delays.

Contractors will start forming Mitchell Point Tunnel with drilling and rock blasting in that area, which means flaggers will create rolling slowdowns to allow both directions of the freeway to be blocked off for 20-minute windows between 9 and 11 am on Tuesdays and Thursdays.

In addition, you can expect single-lane or shoulder closures on I-84 east Mondays through Fridays, and exit 58 off-ramps will be inaccessible. Construction could take up to four weeks.

The original 390-foot Mitchell Point Tunnel was an iconic part of the Historic Columbia River Highway, with five arched windows that overlooked the waterway. Built in 1915, the underpass was closed in 1953 because it could no longer accommodate the increased volume of traffic and larger vehicles. Regrettably, crews destroyed the original shaft in 1966 to widen what is now I-84.

The new tunnel will echo the aesthetics of its predecessor, including five bowed windows, but its length will grow to 655 feet. Once it is finished, the western path will finally be connected to the Hood River segment.

Sixty-eight of the original 73 miles of the highway are now open to travel, either by car or bicycle or on foot. Restoration work is still needed to reopen the Oneonta Tunnel in Cascade Locks, which was damaged in the Eagle Creek Fire of 2017.