The Town of Okotoks is known for its Big Rock.
At 40 metres by 18 metres by 9 metres and 18,000 tonnes,
it is North America´s largest glacial erraticis.
The Big Rock is a glacial erratic (boulder) left from the last ice age 10,000 years ago.
Okotoks derives its name from the Blackfoot name "Okatoks" which means "rock".
The Sarcee called the place "chachosika" meaning "valley of the big rock".
The Stoney name is "ipabitunga-ingay" meaning "where the big rock is".