The Interstate Bridge: Linking Two States Since Nineteen Seventeen

The twin drawbridges you are crossing, or are about to cross, have been carrying traffic between Oregon and Washington since February fourteenth, nineteen seventeen. When they opened, they were greeted by what witnesses described as the largest crowd Vancouver, Washington had ever assembled: up to fifty thousand people turning out to celebrate the first fixed crossing of the lower Columbia River.

Before the bridge, getting from Portland to Vancouver meant boarding a ferry. For a region growing fast on timber, wheat, and manufacturing, that bottleneck was a constant frustration. The Oregon and Washington legislatures authorized a joint bridge commission in nineteen thirteen. Engineers Waddell and Harrington designed a paired lift-span structure, the kind where a central section rises on towers to let tall ships pass underneath, and construction began in March nineteen fifteen.

The American Bridge Company and Pacific Bridge Company finished the job in under two years for about one point seven five million dollars, within the two million dollar bond budget voters had approved. The completed structure stretched three thousand five hundred feet across the Columbia, with a roadway wide enough for two lanes of traffic and two sets of streetcar tracks, immediately connecting Portland's trolley system to Vancouver.

For most of the twentieth century the bridge served well, though its narrow lanes and aging lift mechanisms became increasingly problematic as traffic volumes grew. Today it carries Interstate Five, the primary arterial of the West Coast, over the Columbia in a structure that was designed for automobiles that weighed less than most modern pickup trucks.

Debate over replacing or supplementing the bridge has persisted for decades. Engineers have flagged its vulnerability to Cascadia Subduction Zone earthquakes. The lift spans still rise multiple times a day for river traffic. Whatever eventually replaces it, the nineteen seventeen bridge defined the connection between two states for more than a century, and every driver on this highway crosses on the engineering ambitions of a prewar generation.