Ice formations on the Athabasca Falls during winter, Athabasca River, Jasper National Park, Canadian Rocky Mountains, Alberta, Canada. Jasper National Park forms part of the Canadian Rocky Mountain Parks UNESCO World Heritage Site. The 23-metre Athabasca Falls is not very high by Canadian Rockies standards, but the volume of the river is what makes it one of the most powerful in the Rockies. At the falls, the water passes over a layer of hard quartzite. Over the years, the water has cut into the softer limestone beneath, carving intricate features, including potholes and a short canyon. The Athabasca River is the largest river system in Jasper, with the enormous Columbia Icefields as its source.