The Robertson Tunnel under the city's West Hills
(formally, the Tualatin Mountains) is three miles
long, and its construction presented some significant engineering challenges
in the building of Westside MAX in the second half of the 1990s.
There is a single
stop along this portion of the line, Washington Park. At 260
feet below the surface it's the deepest urban transit station in North
America. Zoo and park patrons use high speed elevators to reach the
This photo gives some indication of how large the
bore is at the station. Smaller tubes carry each of the
two tracks from Washington Park to the outdoors on either side of West
Hills. Trains can be heard when they are far, far off -- long before,
and after, their
lights are visible.