A man from Revelstoke, B.C., is lucky to be alive after he was rescued from underneath the ice on Johnston Creek in Banff National Park on Monday. (CBC)

A B.C. man who got trapped under the ice of a mountain stream survived the ordeal thanks to a group of hikers who spotted him.

The man was walking in Johnston Canyon in Banff National Park on Monday afternoon when fell through the ice covering Johnston Creek, and was washed downstream by the current.

"He'd lost his ice axe and he was trying to break through the surface — basically the ice roof over his head with his helmet — but he couldn't get through," said Aaron Beardmore, a Parks Canada visitor safety official.

The man spent about 10 minutes in the freezing water, breathing the air between the water and ice, before a group of hikers spotted him struggling and were able to pull him to safety about 30 metres downstream, Beardmore said.

"He'd surfaced through a hole in the ice and a bystander ran back to his truck and got a dog leash and a chunk of chain, and they hauled him out of the canyon," he said.

"Those people effectively saved this man's life."

The man, who is from Revelstoke, is reported to be fine.