The 2011 Souris/Mouse River flood in Canada and the United States occurred in June and was greater than a hundred-year flooding event for the river. The US Army Corps of Engineers estimated the flood to have a recurrence interval of two to five centuries. The Souris River begins in southeastern Saskatchewan, flows southeast into North Dakota, then to southwestern Manitoba. It is a tributary of the Assiniboine River, which it meets near Treesbank, Manitoba, and flows east to meet the Red River of the North in Winnipeg.