Bad Route Creek Bridge is a historic bridge which carries County Road 261 across the Bad Route Creek in Dawson County, Montana. The Security Bridge Company built the bridge on behalf of the Montana Highway Department in 1921–22. The reinforced concrete bridge has six spans and is long, making it the longest concrete bridge built by the highway department. Neither the bridge company nor the highway department used concrete extensively, and most concrete bridges in the state only had one or two spans; as a result, the bridge is an unusual and well-preserved example of its type. The bridge was part of a route linking Glendive to Terry, which became part of U.S. Route 10 in 1926. US 10 bypassed the bridge when it was rebuilt in 1950.
The bridge was listed on the National Register of Historic Places on April 28, 2011.