The island was used by Charles Kingsmill, the first Admiral of the Royal Canadian Navy, as his summer residence.
During the 1960s and 1970s, after ownership of the site had passed to Kingsmill's daughter Diana Kingsmill Wright, the island was used in a Quaker programme for training in nonviolence, and also as a co-operative conference centre.
In August 1965, the island was the scene for a role-playing exercise — later referred to as "the Grindstone Experiment" — in nonviolent social defence.
It is now used by Archives & Museum Informatics for seminars and meetings dealing with issues concerning culture and information technology.
It was an accepting and diverse collection of kids mostly from Ontario in the Toronto to Ottawa corridor.