Most of the icy buildup was on the American and Bridal Veil Falls (as opposed to adjacent Horseshoe Falls), Wyllie said.
The Burlington, Ontario, resident walked along the edge of the falls, where he saw the American side glistening with ice.
Only after taking a series of photographs did Perry realize the falls were frozen. "It didn't strike me at first when I took this shot," he said. "I thought it looked like teeth, like a monster's smile."