"The original 1917 bridge represented an enormous financial and engineering accomplishment, shared by Washington and Oregon. It was designed by the renowned engineering firm of Waddell & Harrington, leaders in the field of vertical lift bridge design in the twentieth century. The 1958 bridge was built as a twin structure to the original. The piers of this bridge were assembled from hollow precast segments. The Northbound segment has been listed in the NRHP." [Washington State Department of Transportation website, "Historic Bridges", 2015]

"There was a growing awareness of a definite need for an interstate bridge. The ferry crossing the Columbia River, operated by the Portland Railway Light and Power Company was steadily increasing its business. In 1915 it averaged over 300 vehicles per day and this figure increased by 6 percent the next year. On one summer Sunday over 700 vehicles were ferried across, a crowd which created a long line and prolonged delay." [Freece, D.W., Masters Thesis, 1984, "A history of the street railway systems of Vancouver, Washington, 1889-1926", Portland State University.]

The first Interstate 5 Bridge has a total of 13 Parker-truss style steel spans, with three measuring 275 feet in length and the remaining ten measuring 265 feet in length.

"The bridge over the Columbia River consists of a series of through riveted truss spans with curved top chords; three spans 275 ft. long and ten spans 265 ft. long, together with a small deck girder span at the Vancouvr end, making a total length of 3,531 ft. 5 7/8 ins. between end shoes. Provision for navigation on the river is made by a vertical lift span. The central of three 275 ft. spans is arranaged to lift between towers on the other two, so as to afford a channel 250 ft. wide at right angles to the current of the river and 150 ft. high above ordinary high water." [Harrington and Howard, 1918, The Columbia River Interstate Bridge, Final Report.]

On December 30, 1916, the Interstate Bridge was open to foot traffic due to bad weather and ice on the Columbia preventing the ferry from running.

"1000 CROSS BRIDGE / Ice Blocks Ferry and Interstate Span is Used. / Funeral Cortege Passes / Draw Span Is Lowered for Few Hours in Emergency, and Scores Go to or From Vancouver for Novelty, Despite Cold Wind." [Sunday Oregonian, December 31, 1916]

On January 24, 1917, a streetcar made a trial run over the new bridge between Vancouver and Portland. Opening ceremonies were on February 14, 1917, and the bridge opened for the public use on February 15th. Streetcars had regular schedules between Vancouver and Portland, and continued until 1940 when asphalt was poured over the tracks.

Between 1917 and 1929 a toll of 5 cents per car was levied.

The original bridge is today's northbound lanes.

Construction of the second span (today's southbound lanes) began in 1956 and opened in 1958. The new span was given a rise to allow more boats to pass beneath, to cut back on drawbridge openings. When the new span opened the old span closed for refurbishing and it too was given a rise.

A toll once again was put on the bridge in 1960 (20 cents for cars and light trucks) to help pay for the construction of the southbound lanes and the improvement of the northbound lanes. This toll was removed in 1967.

The entire bridge length is 3,550 feet, with a main span length of 531 feet.

In 1982, the "Vancouver-Portland Bridge" was listed on the National Register of Historic Places (Structure #82004205).

" ... The bridge's twin lift spans are hoisted by electric motors with a capacity of about 50,000 pounds per span. That is far less than the spans weigh, of course, so the lifting process relies on concrete counterweights weighing 300 tons each. The counterweights hang on cables that run over sheaves, or pulleys, at the top of the north and sound ends of the 190-foot-tall lift spans. Atop the counterweights can be seen stacks of two sizes of concrete blocks, weighing 2,000 pounds and 100 pounds. As the traffic wears away the road surface, the blocks are removed from the counterweights to compensate, thereby keeping the lift span's balance weight within the capability of the lift motors. ..."