The Trans-Canada Highway about 20 kilometres east of Canmore reopened late Wednesday morning after the area was hammered by a snowstorm on Tuesday.
Alberta 511 is warning of delays, however, due to the volume of traffic trying to get through the newly opened route.
Westbound lanes in the same area, by Lac Des Arcs, opened at 6:20 a.m.
Earlier, vehicles were in the ditches, and highway crews and tow trucks were trying to clear them out.
Some drivers were stuck on the highway for up to 13 hours.
Police escorted stranded motorists to the warming centre at the Canmore high school but that centre stopped accepting new people as of 7:30 a.m. Wednesday.
Highway 1A from Highway 1X to Highway 133X was closed on Wednesday morning due to what Alberta 511 said was multiple jacknifed semis.
RCMP said there were also cars in the ditch. Highway crews and tow trucks are working to clear the area.
Part of the main highway between Calgary and Edmonton was also closed overnight due to a multi-vehicle crash involving more than 20 vehicles.
Didsbury RCMP said it was a fatal collision.
The Olds Fire Department said Highway 2 needed to be closed in both directions near Carstairs, about 50 kilometres north of Calgary.
The crash happened shortly after 8 p.m. Tuesday and the road didn't reopen until 5 a.m.
Drivers are encouraged to stay off the highways in southern Alberta as crews work to clear ice and snow.
Snowfall warnings have now ended in the province.
With files from The Canadian Press.