Bridge #6391 is an integral part of the Lac Qui Parle Dam. The dam has 12 spillway bays, with each by separated by a concrete wall. These calls are brought up and flared out to be the piers for the bridge. The 11 piers and 2 abutments make a total of 12 spans. The spans are each 20 feet, with the exception of the end spans, which are 18-1/2 feet, which is a total of 239 feet overall. Each span is crossed by a group of 6 reinforced concrete girders, which supports the reinforced concrete deck.

There has been a bridge as part of the dam since the dam was built in the late 1930s. The dam rebuilt in 1996, with most of the bridge being replaced in the process. As the bridge is currently configured, it has two standard traffic lanes, two minimal shoulders, and a set of modern solid concrete guardrails. A sidewalk is located on the downstream side of the bridge deck, while the upstream side of the bridge deck supports the mechanical equipment to operate the dam gates.

The Lac Qui Parle Dam Bridge is a popular place for fishing. The lake is reported to have some of the best walleye fishing in the state.