An avalanche shut down train traffic along Glacier National Park’s southern boundary Sunday night.

BNSF Railway spokesman Matt Jones said a maintenance crew discovered the slide at about 11:30 p.m. Sunday.

Work was still underway at noon Monday to clear the tracks. The slide occurred about 10 miles east of Essex.

“Initial reports indicated there was about seven feet of debris on the tracks,” Jones said, adding that no trains were struck by the avalanche.

“We hope to have it cleared by this afternoon,” he said.

According to The Associated Press, eastbound Amtrak passengers were being bused from Spokane and Whitefish to Shelby while westbound passengers were being bused from Shelby to Whitefish.

Amtrak trains did not arrive as scheduled Sunday night and Monday morning at the Izaak Walton Inn, where about 18 inches of new snow fell Sunday night, said Kelly Fitzgerald, assistant manager at the Essex inn. 

The Flathead Avalanche Center issued a special avalanche advisory Monday rating the avalanche danger as “high” on all slopes across Northwest Montana.

“Very dangerous avalanche conditions exist,” the advisory states. “Travel in avalanche terrain is not recommended and avalanche runout zones should be avoided.”

The avalanche closure Sunday night came just a few hours after U.S. 93 north of Whitefish was reopened following a freight-train derailment on Saturday.

The highway had been closed since 3 p.m. Saturday when 45 empty coal cars derailed just outside Olney. Some of the derailed cars were on a bridge over the highway.

U.S. 93 reopened at 8 p.m. Sunday. During the closure, highway traffic was rerouted on OIney Loop Road.

Meanwhile, a forecast calling for freezing rain and treacherous roads led Missoula County Public Schools to cancel classes again Monday and further postpone high school basketball games that had been called off over the weekend.

That includes basketball games between Flathead and Hellgate. Originally scheduled Thursday, the games were moved to Saturday and then to Monday before the latest postponement.

The University of Montana is holding classes Monday. The university was closed Friday due to weather.