Vista Ridge Tunnels

The Vista Ridge Tunnels are highway tunnels through the Tualatin Mountains ("West Hills") of Portland, Oregon, USA. Located in the Goose Hollow neighborhood, the tunnels pass through a hillside locally known as Vista Ridge which is a half mile (1 km) west of downtown Portland. Sunset Highway, also known as U.S. Route 26, is carried through the tunnels, three lanes in each direction. They are Oregon's busiest tunnels.

The eastbound tunnel is 1001.0 feet (305 m) in length; the westbound tunnel is 949 feet (289 m). Both have 41 ft (12.5 m) of horizontal and 15.58 ft (4.75 m) of vertical clearance. The eastbound tunnel was completed in 1969, the westbound a year later.

There is a six-percent grade through the tunnels. Most of the tunnels' lengths are straight, though they curve southward at the west ends 35°.

The tunnels were built with ventilation shafts which were never used. Instead, the shafts were later adapted for electrical wiring, so as to improve tunnel illumination without marring the tunnels' appearance with visible conduit.