HELENA, Mont. (AP) — A storm has dumped as much as 4 feet of snow on northwest Montana, blocking major highways and isolating one town.

Officials said roads in and out of the town of Browning — just east of Glacier National Park — were closed Wednesday and schools were closed by the heavy snow.

Farther east, the National Weather Service said 2 feet of snow had fallen near Cut Bank.

The Montana Department of Transportation said Interstate 15 was closed for about 75 miles from near Great Falls to near Shelby, along with several other highways in the region.

Weather service meteorologist Jonathan Suk said in Great Falls that the heavy snow was produced by moist air coming in from the Oregon coast and colliding with cold air flowing south out of Canada.