Reaching a mile long and dwarfing its 1931 predecessor, the Stillwater Lift Bridge, the new St. Croix River bridge represents compromises by 28 'stakeholders' who forged an agreement after years of debate. Its rare design makes it only the second major bridge of its kind in the United States. The four-lane bridge, standing 10 stories above the St. Croix and 2 miles south of the Lift Bridge, was built sparingly to avoid overwhelming the scenic view.

Two bridge styles in one

Engineers designed an ‘extradosed’ style to make the bridge more compatible with the St. Croix, a protected ‘wild and scenic’ river. It combines cable-stayed and box-girder styles. Towers were designed to stay below the Wisconsin bluffline.

Cable-stay style

Each cable supports the bridge with 76 plastic-coated steel strands bunched together inside a pipe. These cables are shorter than usual to make the bridge appear sleeker.

Box-girder style

Each girder is a hollow box that gives support without added weight. They are more shallow than a usual box-girder bridge.

Piece by piece

Individual box girder segments were brought in by barge, lifted into place and attached using epoxy and steel cables. In total, 988 segments make up the bridge’s surface.

Pier design

To boaters, piers look ‘open’ to make them feel smaller. Engineers reduced the number of two-pier sets standing in the river from six to five to further reduce the bridge’s presence.

Cable-stay style bridge

Box-girder style bridge

Comparing new bridge to others nearby

Constructing the bridge

Sources: Minnesota Department of Transportation, Sensible Bridge Partnership