This enormous quartzite block, known as the Okotoks Erratic or Big Rock, was carried by the glacier ice from the Rocky Mountains in Jasper to its current resting place south of Calgary, Alberta, Canada. The Big Rock weighs 16,500 tonnes and measures 41X18X9 meters. It is the largest member of the “Foothill Erratics Train”, which spreads from Jasper to Montana in the United States. The migration of the Big Rock took place between18 to 10 thousands years ago. The name “Okotoks” was derived from the Blackfoot word for rock, “Okatok”.