Heavy snowfall in the mountain parks stranded drivers on the Trans-Canada Highway for hours on Tuesday as crews worked to clear crashes that resulted from slippery road conditions.

More than 40 cm of snow fell on the region and the highway was closed down in both directions from Dead Man's Flats to just east of Lac des Arc after a semi tractor-trailer unit jack-knifed and a number of other vehicles ended up in the ditches.

The westbound lanes became a parking lot for hours and were reopened to traffic early Wednesday morning.

The eastbound lanes remained closed for hours and drivers were being turned back to Canmore.

The road was fully reopened at about 11:00 a.m. but drivers can still expect to encounter delays because of the volume.

Some motorists were stranded for up to 10 hours while emergency crews worked to clear the highway.

"We've probably moved maybe a kilometre and now we're stopped again. This is kind of what happens, you get excited that you're going to move and then it comes to a complete stop and the last three times that's happened it comes to a complete stop for hours," said Julie Morris.

The Town of Canmore set up a reception centre for stranded motorists at 1:00 a.m. and about 250 people were sheltered at the local high school but some were forced to spend the night on the highway.

Alberta Transportation worked with emergency officials and contractors to get people out of the area as safely and efficiently as possible.

RCMP say drivers are experiencing extreme winter driving conditions on highways west of Cochrane.

For updates on highway conditions, follow 511 Alberta on twitter, visit AMA Roads Reports and the DriveBC sites.