Deception Pass Bridge, Steel truss bridge in Island County and Skagit County, Washington, United States

Deception Pass Bridge is a steel arch bridge in Skagit County and Island County connecting Fidalgo Island to Whidbey Island, rising about 180 feet (55 m) above the water. The structure consists of two arches resting on a small rocky outcrop called Pass Island, forming a combined length of roughly 1500 feet (457 m).

Construction began in August 1934 with funding from the Public Works Administration and was dedicated on July 31, 1935. Workers from the Civilian Conservation Corps built the approach roads and laid trails in the surrounding park.

The steel structure carries State Route 20 and allows daily traffic between the islands, while pedestrians enjoy views from separate walkways. Below the roadway lies Canoe Pass, a narrow channel that takes its name from the boats that have passed through here for centuries.

Several parking areas provide access to the bridge and hiking trails, requiring a daily pass or Discover Pass. Pedestrian walkways on both sides of the roadway run the full span and allow views of the water and surroundings.

The bridge was the inspiration for the under-bridge sequence in the 2004 video game Half-Life 2, in the chapter "Highway 17". Its steel was supplied by the Wallace Bridge and Structural Co. of Seattle: 460 tons for the Canoe Pass arch and 1,130 tons for the Deception Pass span. Tidal current below reaches 9 knots in Deception Pass and 10 knots in Canoe Pass.