Marquam Bridge

© Gary Wilson Photo|Graphic

Bridge Stats

  • Mile: 13.5
  • Opened: (Lower deck) October 4, 1966 (Upper deck) October 18, 1966
  • Type: double deck steel through (Double-deck steel through cantilever truss)
  • Engineers/Designers: ODOT
  • Owner: State of Oregon
  • Total Length: 1,043.’ 8”
  • Main strong Length: 440’
  • GPS Coordinates: 45.507791, -122.669381


Designed by the Oregon State Highway Department Bridge Section, the Marquam is a through-truss, fixed bridge with a suspended cantilever center span. It opened in 1966 as an element of Portland’s Interstate transportation system and was the city’s first double-deck highway bridge built exclusively for vehicular traffic.

It was named for Philip Marquam, a 19th century transportation advocate, but its strictly functional appearance engendered, ironically, an outcry for public participation in future bridge designs—and periodic discussions of the merits of its removal since being finished nearly a half century ago.

Willamette Light Brigade does not yet have a lighting design concept for the Marquam.