Greenstone is a single-tier municipality in the Canadian province of Ontario with a population of 4,636 according to the 2016 Canadian census. It stretches along Highway 11 from Lake Nipigon to Longlac and covers 2,767.19 km2 (1,068.42 sq mi).

King's Highway 11, commonly referred to as Highway 11, is a provincially-maintained highway in the Canadian province of Ontario. At 1,784.9 kilometres (1,109.1 mi), it is the second-longest highway in the province, after Highway 17. Highway 11 begins at Highway 400 in Barrie and arches through northern Ontario to the Ontario–Minnesota border at Rainy River via Thunder Bay; the road continues as Minnesota State Highway 72 across the Baudette–Rainy River International Bridge. North and west of North Bay, Highway 11 forms part of the Trans-Canada Highway and is part of MOM's Way between Thunder Bay and Rainy River.