The Lake Washington Ship Canal was completed in 1917. In the process, the creek connecting Lake Union and Salmon Bay was enlarged and became part of the canal, deep enough and wide enough for oceangoing vessels to enter. The old trestle bridges were taken down and the Fremont Bridge was built. The bridge employed technology developed in Chicago in 1898.
The Bridge Engineer was F. A. Rapp, and the pier design was by D. R. Huntington. The counterweight pits and workings are housed in two concrete piers, each of which has a tower.
In Made to Last: Historic Preservation in Seattle and King County Lawrence Kreisman writes:
"The Fremont community attaches great value to the bridge as an identifiable and historically significant landmark. Bright orange was selected by the Fremont Community Council to distinguish their bridge from other bridges throughout the city, but it faded quickly, and the bridge is now painted blue with orange accents."
The current colors of the bridge were selected by a 1985 poll of Fremont residents and by the Fremont Arts Council. As of 2005, the bridge opens about 35 times a day. The community celebrated its 500,000th opening on September 20, 1991. By January 2006 the bridge had opened for marine traffic some 566,000 times.
Between September 2005 and June 2007, the bridge's 90-year-old approaches were replaced. This required the rerouting of Metro buses, many lane closings, and some bridge closings. The bridge's traffic signals, sidewalks, and curbs were also improved. SDOT reopened Fremont Bridge's four lanes on May 18, 2007. The bridge's mechanical and electrical structures will be renovated during the next year.