Constructed in 1931 and listed on the National Register of Historic Places, the Stillwater Lift Bridge had served its purpose for nearly 90 years. It long outlasted what designers thought would be its useful life and, over the years, caused congestion throughout historic Stillwater.

The use of precast and cast-in-place concrete on the approach spans and the extradosed unit on the new bridge was essential in meeting the goals of the visual quality manual prepared by MnDOT.

These include:

• The parts of the bridge look as if they were found in nature, or shaped by natural forces.
• The vertical pier forms are reed-like; the girders are rounded and tapered like bones or tree branches; and walls, barriers and railings are curved and blended into the larger forms.
• Transitions are gradual and smooth; edges are soft and curved; and colors are unified and natural expressions of their materials.

The curved “organic” nature of the girder webs are clearly exposed from both viewing directions and visually provide for consistent leading edges on both sides.

The St. Croix River is protected under the U.S. Wild and Scenic Rivers Act. It is surrounded by tree-lined bluffs and pristine shorelines. With 16 ponds, the new system filters out sand, sediment, gravel and nutrients, while also reducing the quantity of phosphorus entering the St. Croix River from stormwater by nearly 25%.

Due to highly erodible soils on the Wisconsin bluff, construction crews used less-invasive techniques that included constructing the drainage structure by hand, operating small machines and equipment, and using a temporary trestle system that reduced impact to the bluffs below Pier 13 and the east abutment.

To minimize work on the Wisconsin bluff line, the new bridge was aligned with an existing ravine, reducing the need to cut into the bluff and creating a smooth transition from highway to bridge.

The project took extra care to protect nature around the site and prevented disturbing an active bald eagle nest by maintaining a 300 ft perimeter — later to observe that three eaglets were hatched in the spring, instead of the normal one hatchling.Further, the project required that Higgins eye pearly mussels that lived in the construction area be relocated. These native mussels were eventually transplanted back into the river and other tributaries. In Wisconsin, seeds of the endangered Dotted Blazing Star flowers were gathered from flowers and stored for future planting before crews relocated the flowers.

While the light brown paint matches the adjacent bluff, painters opted to roller-apply the paint over the waterway instead of spray it on. This eliminated overspray from paint guns, which would have ended up in the water. The contractor utilized a series of checks and balances including curtains and tarps to ensure no items were dropped into the river during construction.