Alberta is the site of many natural wonders and Okotoks Erratic is one such wonder that “ran” from the present-day site of Jasper National Park to 55 km south of Calgary.
A glacial erratic is any rock that was once transported by a moving and now-melted glacier. In Okotoks, you can take in one of the larger of these formations at the Big Rock site, located on AB-7, about 10-minutes outside of town.
The town received its name from this geographical landmark: the Blackfoot name for rock is ‘okotok,’ and the rock has cultural significance to the Blackfoot people, being a feature of a story centred on Napi, a supernatural trickster, and how the giant split down the middle of the rock came to be. The site was also home to different ceremonies and used as a place to document significant events through pictographs.
There are a few short walking trails taking you all around the Big Rock, and a viewing platform. The interpretive boards will tell you the geological history of how the light grey, pink, to purplish in colour quartzite erratic that was once part of a mountain formation in Jasper National Park was transported across the valley due to a rockslide that happened about 30,000 years ago.
From here, you can get striking foothill views, and mountain views on clear days. The rock itself is NOT to be climbed, and the quartzite creates slippery and delicate surfaces all along the rock. It is also a protected area by the Federal Government and an important part of the Indigenous Blackfoot culture.
Plan your trip to Big Rock or Okotoks Erratic
What: The Okotoks Erratic, or ‘Big Rock,’ which is a result of glacial movement from 10 000 to 30 000 years ago. This 16 500-tonne quartzite boulder pops out of the flat prairie landscape of Okotoks at 9-m tall, 41-m long and 18-m wide. As the sediment has been layered and buried over time, the weight of the boulder has helped cement it in place in the ground.
Best time to go: year-round
How much: free
AB-7, Black Diamond, AB
Whether coming from the north or south of Alberta, you’ll need to take Highway 2 or Highway 22 to Highway 7. The Big Rock is on the westbound side of Highway 7, about 10 minutes west of town.