Three climbers were injured — one critically — when they were hit by a falling tree near Lake Louise in Banff National Park.

Parks Canada responded to three climbers at the Outhouse Wall at the Back of the Lake climbing area on Tuesday morning.

A report by the Association of Canadian Mountain Guides says it's believed high winds toppled a brittle tree.

It says the tree fell 80 to 100 metres and hit the climbers standing at the bottom.

One climber was taken to hospital in critical condition by STARS Air Ambulance.

A Parks Canada spokesperson says a second climber was transported by ambulance to Banff Mineral Springs Hospital and the third was able to walk out from the area on their own.

The association says the area is not closed, but there are dozens of dead trees above the climbing spot.

It suggests wearing a helmet and leaving the area when there are high winds.