The Okotoks Erratic, known as Big Rock, is an 18,200-ton boulder that was transported from the Jasper National Park mountain formations on top of a glacier between 10,000 to 30,000 years ago.
Okotoks is named after Big Rock, derived from the word “okatok,” the indigenous Blackfoot peoples word for rock.
The Big Rock is the largest of the foothills erratics train, a series of boulders stretching over 700 kilometres along the eastern foothills of the Rocky Mountains from Jasper to Montana.
In addition to the scientific history of Big Rock, the indigenous Blackfoot peoples had their own legend to tell of the formation.
Blackfoot elder Stan Knowlton shared version as his elders and chiefs told it to him when he was a young boy on the Piikani Reserve.
While the Blackfoot legend of Big Rock has many versions, all feature Napi, the supernatural trickster of the Blackfoot.
The legend tells of Napi having cheated someone out of a nice buffalo robe, only for the Sun and Wind to take their revenge on Napi and his tricks. The Sun makes it so hot that Napi gives the robe to Big Rock. Only after he has given away the robe does Wind begin to blow such cold air that Napi goes back to the Rock to take back the robe.
The Rock refuses to give back the robe, so Napi takes it, assuming the Rock will not be able to follow.
The Rock, however, begins to roll after Napi, across the prairies, coulees and rivers.
Eventually swallows, or bats depending on the speaker, swoop in to help Napi, eventually breaking the Rock in two and stopping it in its tracks at its final resting place just west of Okotoks.
When asked about the different versions, Knowlton shared what his elders told him when he asked the same, that stories are like grass.
“Grass looks like it has a lot of different leaves on it, but when you get to the bottom it’s the meaning that is in the root. As long as you tell a story to the best of your ability, in the end it all comes to mean the same thing,” he said.
In the 1970s, the Big Rock was the first “natural feature” to be designated as an official provincial historic site. The site and parking lot was offcially opened year-round in early 2015.
The Big Rock is located 10 kilometres west of Okotoks on Highway 7. Because of its historical significance, climbing on the Okotoks Erratic is not permitted.
This content was produced by our Western Wheel newsroom for Foothills Visitor & Adventure Guide and Great West Media's 2022 Hot Summer Guide.