A Jasper man says he was stranded on a bus for almost 18 hours after it became stuck in deep snow this week on Highway 93 in Banff National Park.

David Harrap was on a Brewster bus from Calgary to Jasper the afternoon of Oct. 18 when the snow began piling up on Highway 93, also known as the Icefields Parkway. The bus became stuck at around 5 p.m. in an area called Big Bend, a hairpin turn that's wedged below looming mountainous peaks.

The bus driver tried everything to maneuver the bus out of the snow, Harrap said. As the snow continued to fall, he estimates more than 50 other vehicles around them became stuck on the hill.

"It was complete shambles up there," he said. "There wasn't a ton of snow on the road, but it was really bad snow. It was really slippery, it was wet snow."

There were seven people on the bus, including the driver, Harrap said. The area had no cell service but the bus driver had a two-way radio and tried to contact RCMP and Parks Canada with it. A supervisor from Parks Canada came out and said a snowplow was on the way, but then determined conditions were too dangerous to send it, Harrap said.

The driver of the bus managed to secure some chains to the tires, but still could not free the bus. Some staff memebers from the nearby Icefields Centre managed to bring some bananas, granola bars and water to the bus, Harrap said.

Realizing they wouldn't be moving anytime soon, the passengers settled in for the night.

"All of us on the bus, we didn't know where we were," he said. "You just try to sleep the best you can. You think someone's going to show up.

"It kept snowing all night and eventually we had close to 40 centimetres on the ground."

Parks Canada staff arrived at around 10:30 a.m. the next day to clear the road and the bus was able to continue on to Jasper, Harrap said.

Harrap said around 40 centimetres of snow fell throughout the night before the bus could be freed. (Supplied/David Harrap)

'Significant early snowfall,' Parks Canada says

In an email, Parks Canada spokesman Steve Young confirmed Highway 93 northbound between Jasper and Saskatchewan Crossing had to be closed the evening of Oct. 18 due to "significant early snowfall."

The Big Bend area was particularly hit hard by the snowstorm and the incline and deteriorating conditions rendered the area impassable, he said. Parks Canada staff were dispatched at daylight the next day to begin clearing the road, Young added.

Motorists are urged to be prepared for early winter conditions while travelling along the Icefields Parkway. It's recommended motorists carry a winter emergency kit and proper winter clothing in their vehicles, and check Alberta 511 for updates on road conditions.

Snow tires are mandatory on the Icefields Parkway starting Nov. 1.

Harrap said the temperature hovered around 0 C overnight as the passengers slept on the bus. He says some tourists on the bus and in other vehicles around them were not dressed for the weather.

It was like we had been completely abandoned. - David Harrap, bus passenger

He says buses going through mountainous areas with no cell reception should be outfitted with satellite phones or hotspots in case of emergencies.

"To be left that long, if there had been a medical emergency .... I don't know what would have happened, because it was like we had been completely abandoned," Harrap said.

Brewster Travel Canada is refunding tickets to six of the passengers who spent the night on the bus, Harrap said.

CBC reached out to Brewster Travel Canada for comment but has not received a response.