South Dakota breaks ground on the largest bridge project in its DOT's history
A $290 million, 5,665-foot crossing over the Missouri River replaces a 1966 span, with the longest bridge in the state taking shape between 2027 and 2031.
The bridge that has carried traffic across the Missouri River between Platte and Winner, South Dakota, since 1966 has spent six decades doing what it could with the materials and engineering assumptions available in the mid-1960s. On October 22, 2026, Governor Rhoden led a groundbreaking ceremony that committed $290 million to a full replacement, the largest project in the South Dakota DOT’s history, with the existing span staying open while the new one is built alongside it.
The physical scale of the job is what makes the number less arbitrary than it might first appear. The new crossing will be a 5,665-foot span — the longest bridge in the state — and 36 feet wide, eight feet wider than the structure it replaces per the Mitchell Republic’s account of the event. The foundation work is where the real engineering challenge sits: pilings four and a half feet in diameter, drilled roughly 200 feet down to bedrock, to hold a structure designed for a 100-year service life against a river that doesn’t behave itself in winter.
Ames Construction is the awarded contractor, with construction running from 2027 through 2031. The new bridge is slated to be in place by 2030, with the full construction sequence — demolition of the old span, road repaving, and final work — completing in 2031. The SDDOT’s own framing emphasizes that drivers will not lose the crossing at any point during construction; the 1966 bridge stays open for the duration.
Funding is a layered thing, as these projects tend to be. The state delegation brought $25 million to the table, and a $65 million Federal Highway Administration grant forms the other visible pillar of the project’s financing, with the remaining balance drawn from state transportation funds. The FHWA’s presence at the groundbreaking was not merely ceremonial: the agency’s administrator attended alongside both of South Dakota’s U.S. Senators, and all three of the state’s Congressional members were on the ground at the event.
What makes a $290 million bridge in rural South Dakota matter beyond the immediate communities it serves is the simple arithmetic of a sixty-year-old structure reaching the end of its useful life. The 1966 span was a reasonable piece of infrastructure for its time. It was not designed for the truck weights, winter loads, or traffic volumes it now carries, and the cost of continuing to patch it was becoming, by any reasonable measure, a false economy. Replacing a Missouri River crossing at that scale is not something a state does every decade; the SDDOT’s own characterization of this as its largest project in its history is an honest way of saying the next time it happens will be measured in years, not quarters.