Between 2006 and 2009, GRI assisted ODOT and the Western Federal Lands Highway Division (WFLHD) with restoration of the tunnel. Restoration included installation of about 250 rock dowels in the tunnel, installation of mine straps, strip drains, a structural shotcrete liner, and construction of a non-structural wood liner. A series of steel sets were installed near the East Portal in an area of particularly weak and weathered rock and thin roof cover.

In September 2017, the entire wood liner of the tunnel burned during the Eagle Creek Fire. In 2019, GRI performed a tunnel inspection to evaluate damage from the fire and provided geotechnical recommendations for repair of the tunnel.

Location: Multnomah County, Oregon

Owner: ODOT; funded by FHWA

Market Sector: Federal, Transportation

Services: Geotechnical Engineering, Geologic Hazards