The Four Bears Bridge crosses the Missouri River near New Town, where the river is widened by the Garrison Dam, forming Lake Sakakawea. Shapes, colors, icons and images significant to the cultural history of the Three Affiliated Tribes come together to create a design that is contextually sensitive to the Native American environment. The design was developed through a design charette process to gain input from tribal representatives and local citizens. Severe winter icing of the deep lake resulted in the use of precast cofferdams that function as both a template for driving the steel piles and as a lost form for the footings, eliminating the expense of driving sheet piling during construction. The cofferdam shape is a 13’ tall conical frustum with a base diameter of 39’, chosen to deflect ice floes. The project included a design charette with the Three Affiliated Tribes, design of the precast concrete segmental bridge, design office support during construction and construction engineering inspection on site.