A tractor trailer crashed and spilled a liquid substance on Interstate 90 between Deborgia and St. Regis Wednesday.
Acccording to information from the Montana Department of Transportation, the crash closed both eastbound lanes at about 12:38 a.m.
By 9:42 a.m., one westbound lane was open.
The crash is being investigated and that is expected to take an extended amount of time.
Traffic is being rerouted off I-90 and on to other area roads.
Officials say motorists should expect delays, detours and to drive to reduced speeds.