Back in ’72, there was, on the Saturday of Victoria Day weekend, a gathering upon Prince’s Island Park.

The description in the Calgary Herald, in which the above photo ran, read:
Magnificent May weather brought Calgarians out from the winter’s doldrums over the long weekend. Saturday’s Recycling Festival on Prince’s Island Park drew a large crowd–most of them young–for a day of music, food and companionship of the like-minded.
I’ve been unable to find out who organized the event, who the performers were, or any greater description of it beyond what appeared below the photo. I’d like to think that The Stampeders were cranking out Sweet City Woman, which had won a Juno for Best Single of the year just three months prior. Of course, by then, they were already five years gone from Cowtown.
