HELENA — A tractor-trailer overturned Tuesday, forcing authorities to close a portion of Interstate 15 outside Helena, as much of Montana was hit with its first major snowstorm of the season.
A number of accidents with injuries were reported as blowing snow and icy roads made for treacherous driving conditions, Montana Highway Patrol dispatch supervisor Michele Rogers said.
"We have crashes everywhere," Rogers said. "We're advising people to stay off the roads if they can."
Forecasters said the storm was expected to pass through the state fairly quickly, leaving scattered snow showers by Tuesday night.
Strong wind apparently blew over the tractor-trailer on I-15 near the Sieben Ranch exit about 25 miles north of Helena. Several other vehicles ran off the roadway nearby, Rogers said.
It was not immediately clear how many people had been injured. Emergency crews were responding.
The Highway Patrol has closed southbound I-15 at Wolf Creek. Northbound lanes were still open, though authorities were advising drivers to stay off the highway except for emergencies.
The National Weather Service has issued a winter storm warning for much of the state. Near whiteout conditions were expected with snow falling at about an inch an hour and wind gusts as high as 55 mph from the Helena valley east to Lewistown and south to Bozeman.
Up to 6 inches of snow was expected to fall at lower elevations, and as much as a foot was forecast above 5,000 feet.
Heavy snow also was expected from the Rocky Mountain Front east along the Hi-Line, weather service meteorologist Nick Langlieb said.
High winds with gusts up to 55 mph were expected in the northern and central part of the state from Cascade County to East Glacier County, Langlieb said.
The area with the most snowfall in the past 24 hours was 21 inches in the Showdown Mountain Ski Resort in the Little Belt Mountains.