Footprints on a snowy mountaintop dangerously close to the edge of a cliff prompted rescue officials to post the picture on Facebook as a prime example of how not to stay safe.

The trail of footprints in the photo shot March 13 appear to show that one or more hikers walked to the edge of an alpine ridge for a look at the view.

The problem is, part of that ridge is actually a cornice, which extends out over the 300-metre cliff face of the east side of Mount Rundle, near Canmore.

A cornice is an overhanging mass of hardened snow that juts off the ridge of a mountain. It might look solid, but appearances are deceiving.

"It's probably one of the most dangerous things you can do in the mountains, is to walk on a cornice," said Kananaskis Country Public Safety Specialist Jeremy Mackenzie.

"A lot of times cornices are relatively hidden. They're not as obvious as you might wish they were, and so any time you're approaching a mountaintop or a ridgeline feature, there is the potential that there could be a cornice there, so don't necessarily trust the snow unless you take that time to evaluate it."

Safety experts suggest avoiding this type of terrain unless you have the proper mountaineering training to detect and avoid cornices.

"This time of year, cornices fail on a regular basis. Avoid being on or under them at any time," the safety organization said in its Facebook post.

"Use a probe or ski pole to identify where the snow starts to thicken on the good side of the cornice and leave it a wide berth. When they fail, they can pull back and release from what appears to be flat, safe ground."

Mountain safety expert Chris Stethem says cornices are often hard to detect, especially when people are distracted by the mountain views or focused on taking photos.

"They're very deceptive, cornices, you can't really see the edge until you're at the edge or over the edge."