Arlington Heights in Portland in Multnomah County, Oregon — The American West (Northwest)
The Robertson Tunnel
Photographed by Ian Lefkowitz, June 26, 2026
1. The Robertson Tunnel Marker
Two hundred and sixty feet below here, MAX light rail trains run in parallel twin tunnels three miles through Portland’s West Hills. A joint venture of Frontier-Kemper Constructors and Traylor Bros. built the 21-foot-diameter tunnels between July 1993 and November 1997 at a cost of $183 million dollars. For over four years, as many as 350 workers per day labored in three shifts, day and night, six days a week, to mine the tunnels and line them with concrete.
From the east, a 300-foot-long tunnel boring machine chewed two miles through 16-million-year-old basalt from ancient volcanoes. From the west, workers used explosives to mine a mix of lava rock and hardened wind-blown silt that was unsuited for mining with a boring machine. The two sides met in the westbound tunnel 300 feet beneath the Sylvan business district on December 29, 1995, and in the eastbound tunnel on August 14, 1996. Stout steel ribs on four-foot centers form the tunnel’s structural frame, covered by a foot-thick concrete lining.
Frontier/Traylor also mined the underground station cavern, the two 31-foot-diameter elevator shafts leading to the surface, and
this page online
The twin tunnels are named in honor of William D. Robertson, Jr., 1947–1997, a former president of the Tri-Met Board of Directors.
Erected by Tri-Met.
Topics. This historical marker is listed in these topic lists: Bridges & Viaducts • Railroads & Streetcars. A significant historical date for this entry is December 29, 1995.
Location. 45° 30.639′ N, 122° 42.997′ W. Marker is in Portland, Oregon, in Multnomah County. It is in Arlington Heights. It can be reached from the intersection of Southwest Canyon Road and Southwest Zoo Road, on the left when traveling north. Touch for map. Marker is at or near this postal address: 4033 SW Canyon Rd, Portland OR 97221, United States of America. Touch for directions.
Regionally, this marker is in Oregon’s Columbia River Gorge and in the Willamette Valley. It is also on the American Pacific Coast, in the Pacific Northwest, and in the Lewis & Clark Corridor.
Photographed by Ian Lefkowitz, June 26, 2026
2. The Robertson Tunnel Marker
The marker is located on top of the Washington Park MAX Station, overlooking the Oregon Zoo.
Other nearby markers. At least 8 other markers are within walking distance of this marker: A different marker also named Robertson Tunnel (a few steps from this marker); Les AuCoin (within shouting distance of this marker); Oregon Vietnam Veterans Living Memorial (about 500 feet away, measured in a direct line); Garden of Solace (about 700 feet away); 1959 – 1965 (about 700 feet away); MIA (approx. 0.2 miles away); 1966 – 1967 (approx. 0.2 miles away); 1972 – 1976 (approx. 0.2 miles away). Touch for a list and map of all markers in Portland.
Also see . . . Robertson Tunnel (Wikipedia).
There is one station within the tunnel at Washington Park, which at 259 feet (79 m) deep is the deepest subway station in the United States and the fifth-deepest in the world.(Submitted on August 31, 2026, by Ian Lefkowitz of New York, New York.)
Photographed by Ian Lefkowitz, June 26, 2026
3. The Robertson Tunnel
The Robertson Tunnel is found within the MAX station. Lettering and an interior plaque mark the completion of the tunnel.
Photographed by Ian Lefkowitz, June 26, 2026
4. The Robertson Tunnel
One of the tunnels found nearly 250 feet below the earth's surface.
Credits. This page was last revised on September 7, 2026. It was originally submitted on August 31, 2026, by Ian Lefkowitz of New York, New York. This page has been viewed 15 times since then. Photos: 1, 2, 3, 4. submitted on August 31, 2026, by Ian Lefkowitz of New York, New York. • James Hulse was the editor who published this page.
