 A monument at the east end of the lake is a key point in the demarcation of the northeast–southwest boundary between Ontario and Manitoba.Located on the lake are the First Nations communities of Wasagamack, St. Theresa Point and Garden Hill and the northern settlement of Island Lake which in 2011 had a combined population of 7,120.Wasagamack had a population of 1,411 in the Canada Census of 2011 and St. Theresa Point had 2,871.