HELENA- Lewis and Clark County public works staffers are in the process of closing the Dearborn River Highway Bridge located 18 miles south of Augusta.
County Chief Administrative Officer Roger Blatz tells MTN News the 7-ton limit bridge on Highway 434/435 was damaged Tuesday when a tractor-trailer carrying a 35-ton load crossed the structure.
Blatz says the decking, railing and jersey rails of the bridge all suffered damage. The bridge was built in 1897.
County Public Works Eric Griffin says his crews are either on-scene or on the way with materials to close the bridge until further notice.
Blatz says the county has asked the Montana Department of Transportation to inspect the structure as soon as possible.
Travelers are being told to use Highway 200 instead of Highway 435, which links Wolf Creek and Augusta.
No word yet on a damage estimate to the bridge.