The municipality's name comes from the former county of Grenville, one of the two municipalities that was merged into the current one, and the name of the Rivière Rouge, which crosses the municipality from north to south. The name Grenville was chosen to honour the memory of George Grenville, a British politician. The origin of the river's name is uncertain, but most likely due to the water's reddish tint due to oxidation of the iron in the river bed. The municipality was created in 2002 through the merger of the municipality of Calumet and the county of Grenville.
The Rivière Rouge and the area's development
From the First Nations to the explorers of New France, from the coureurs des bois to the establishment of the colonies, the Rivière Rouge and the Outaouais River shaped our area's development. Before the French arrived in America, the Rivière Rouge was part of the Algonquin territory, and was known as the river of the Great Spirit. In the early days of the American Indians and the French presence in the area, the Ottawa River was one of the main communication routes inland, and one of the key commercial routes of New France.
In the first half of the 19th century, the Hamilton brothers from Hawkesbury controlled a large portion of the forests in Grenville County and the Rivière Rouge valley.
Given its strategic importance under the French regime, which was amplified by its historical significance during the fur trading period, and regenerated through forestry, the Rivière Rouge is one of those symbolic spots whose potential has been one of the pivotal levers in the region's socioeconomic development.