Recent heavy rains led to a rock slide early Tuesday morning that blocked most of Highway 12 West near the Graves Creek Road turnoff.

photo courtesy of Bill Burt

Maintenance supervisor for the Missoula division of the Montana Department of Transportation, Steve Felix, said the slide occurred just after 5 a.m. and that highway department personnel were able to guide smaller vehicles around the massive boulders that littered the roadway. Felix said that situation changed at about 9 a.m.

"Right now, Highway 12 is closed to through traffic at mile marker 20, and up to the Montana- Idaho border on the west end of Highway 12," Felix said. "We had a large rock slide that came through this morning and we have been forced to close the road because we've got some instability up where the slide occurred."

Felix said the boulders littering the roadway are too large to move with heavy equipment, so they will have to use explosives.

"We're in the process of blasting to bring some additional rock down,and we'll have to blat the rock that's already on the roadway," he said. "We've got one really big chunk of rock that's several hundred tons on the roadway."

Felix said the cleanup will take at least through the day and perhaps into tomorrow.

Captain Bill Burt with the Missoula County Sheriff's Office said drivers can still use Petty Creek and Graves Creek road to get to Interstate 0, but that road is only accessible to passenger cars and trucks, while semi-trucks will not be able to maneuver the switchbacks on the narrow road.