The Montana Department of Transportation has closed Highway 191 from Harlowton to Eddies Corner.
MDT reports there is zero visibility from blowing and drifting snow.
Roads are snow-covered and icy.
Drivers are asked to avoid the area and use an alternative route.
Road conditions appear to have improved around Great Falls and along Interstate 15, however, some areas are still reporting reduced visibility.
The road closures follows several severe driving conditions alerts issued Friday morning in north-central Montana.
Sub-zero temperatures are expected this weekend and lows in the area could be as cold as -30 degrees Friday night.
Montana Department of Transportation road conditions: