Update: Temporary bridge over Flat Creek installed for oversized loads

Published on November 01, 2024

Updated 8/25/25
Lewis and Clark County has installed a temporary bridge over Flat Creek on Birdtail Road located approximately 3.8 miles north from U.S. Highway 287 to provide access for oversized.

In November 2024, Lewis and Clark County restricted traffic on the 5-ton weight limited bridge over Flat Creek on Birdtail Road to single light-passenger vehicles following an inspection by the Montana Department of Transportation. The County began exploring options for a temporary bridge that could accommodate the heavy agricultural loads needed by local landowners until a new bridge could be designed and built.

After identifying a detour location on private land, Lewis and Clark County entered into a 5-year Temporary Construction Agreement with the Dearborn Ranch, LLC to install a temporary bridge. The County was able to purchase a used steel-construction TrueNorth 50’L x 16’W bridge, constructed in 2018, from the City of Wallace, ID for $50,000 through a sealed bid, and installation was completed on August 18, 2025. The bridge, which is intended for agricultural traffic over five tons, is gated (not locked) and signed with “Keep Gate Closed” at the request of the landowner to protect private property and livestock. Light-passenger vehicle traffic should continue to use the original bridge.

Lewis and Clark County is actively seeking grant and other funding opportunities for design and construction of a new bridge to replace the original Flat Creek Bridge.

Original Story posted 11/1/24
Helena, MT – Beginning Monday, November 4, 2024, Lewis and Clark County will restrict traffic on a 5-ton weight limited bridge over Flat Creek to single light-passenger vehicles only following an inspection by the Montana Department of Transportation.

Out of concern for public safety, the decision to restrict the bridge was made after evidence indicated that loads exceeding the weight restriction had crossed the bridge and additional safety precautions needed to be implemented. No detour route around the bridge is available. Any traffic weighing in excess of a single light passenger vehicle should seek an alternative route. The bridge is located on Birdtail Road approximately 3.8 miles north from U.S. Highway 287.

Lewis and Clark County will begin efforts to design a bridge replacement and actively seek out grants or other funding for future replacement.

For more information, contact the Lewis and Clark County Road and Bridge Department at contact 406-447-8031. Office hours are Monday through Friday, 6:00 A.M. to 4:30 P.M.

###