2006 marked the 50th anniversary of the publication of the first comprehensive study of this remarkable feature by Dr. A. MacS. Stalker, Geological Survey of Canada. Understanding of its origin has been key to reconstruction of the ice-age history of Alberta as well as understanding when and how the first people entered the Americas. Dr. Stalker's investigation was one of the most fundamental contributions to the understanding of the ice age history of the Alberta Foothills.