Rock Solid: This Alberta glacial erratic is the largest in the world

Alberta is an incredible province with a ton of surprises, but few have a presence like ‘Big Rock,’ an enormous landmark near Calgary.

Located west of Okotoks, you’ll find an erratic that weighs an estimated 16,500 tonnes or 36.3 million lbs.

Not impressed? You must be a tough cookie to crumble because this particular boulder is officially the largest of its kind and has even been recognized by Guinness World Records.

What’s even more interesting, however, is how it ended up just outside the town in the first place.

According to the Government of Alberta, this oversized mass travelled over 400 km before finding a home

“Big Rock was originally part of a mountain formation in what is now Jasper National Park. During the last ice age – about 30,000 years ago – a large rockslide crashed debris onto the surface of a glacier that occupied the present-day Athabasca River valley, and this debris, including Big Rock, was carried out of the mountains on the glacial surface,” they explain.

“As the ice melted and the glacier retreated to the mountains, the rocky debris, including this huge erratic, were deposited across the prairies.”

Another fact worth noting is that since making its way south, the rock has become a place of significance to the Indigenous Blackfoot peoples, who are responsible for its moniker.

The erratic’s name is actually derived from their word for rock, which is “okatok. ” Sound familiar? 

Due to its impressive size and its place in the big book, it has also become a popular tourist destination and was designated a Provincial Historic Resource.

Want to check it out? It’s hard to miss!

Measuring 9 metres tall, 41 metres long and 18 metres wide, Big Rock is approximately the size of a three-storey apartment building.

If, of course, you choose to visit please be respectful and don’t climb on it.

It really is something else and it’s important we keep it as is. Enjoy and happy adventuring!

Big Rock Erratic – Okotoks, Alberta

Where: AB-7, Black Diamond, Alberta

Related Posts:
An “unmatched” gem: This Alberta Park is home to some of the most important fossil discoveries ever made
This well-preserved Alberta ‘ghost town’ has a pizza party once a month

Parts of Alberta are currently facing significant fire activity. If you’d like to help the many communities affected, please head to the Canadian Wildfire Fund