The most widely accepted story about the origin of the name of the flats arose out of an incident that occurred in the early part of the twentieth century. Jean Marret came from France to the Canmore area around 1900 to operate a dairy farm. His brother François joined him shortly after. François did not like life as a farm hand and spent the next three years working at odd jobs in Canmore and Cochrane. In an alleged act of self-defence on May 10, 1904, François Marret murdered his brother Jean while he was asleep in bed, then threw the body into the Bow River near this spot. The name for the flats was approved in 1958, and the locality in 1984.