[9] The east tunnel entrance is near the Vista Bridge at the edge of the Goose Hollow neighborhood at the foot of Washington Park.

Plans to build a light rail line to serve Portland's western suburbs in Washington County emerged in 1979 with a Metro regional government proposal to extend what would become the Metropolitan Area Express (MAX) from its inaugural terminus in downtown Portland farther west to the cities of Beaverton and Hillsboro.

[11][12]: 2-4  A majority of jurisdictions had selected a Sunset Highway light rail alternative by June 1982,[13] with the Portland City Council the last to adopt a resolution supporting this route in July 1983.

[14] Metro subsequently moved forward with this alternative, and the Urban Mass Transportation Administration (UMTA) authorized $1.3 million in funds to begin a preliminary engineering study.

[15]: P-1 [17] Prior to the start of preliminary engineering efforts, the Portland City Council asked TriMet to consider building a rail tunnel through the West Hills instead of following the Sunset Highway alternative's proposal to run tracks on the surface alongside Canyon Road.

TriMet's engineers noted that this surface option would carry a steep six- to seven-percent grade as opposed to only two percent in a tunnel.

[25] Construction began in the summer of 1993 at the west end, employing the conventional mining technique of drilling and blasting due to the loose mixture of materials.

About a thousand workers from 230 construction firms were involved in the 18-mile westside MAX line, including those who built the tunnel and installed the reinforced concrete liner, tracks and wiring.

The elevation at the west end is higher than the east but there is very little perceptible slope except for several gentle, short grades which exist presumably to follow the easiest-to-bore rock stratum.

After the station, it passes under the south side of the World Forestry Center's main building and turns 4° northward (267°) and continues for its longest straight stretch of 900 meters (3,000 ft).