The river was discovered (1734) by the LA VÉRENDRYE expedition; a French post, Fort Maurepas, was built on the delta that year and Fort Rouge (1738) at the forks.
Red RiverRed River, 877 km long (to the head of the Sheyenne River), rises in Lake Traverse on the Minnisota-South Dakota border, as the Bois de Sioux River, joins the Otter Tail River and flows directly north past Fargo and Grand Forks, crossing the Canadian border between Pembina, North Dakota, and Emerson, Manitoba. It receives its major tributary, the ASSINIBOINE, at the "forks" in WINNIPEG and enters Lake Winnipeg through a labyrinth of channels. As the last glacier receded, the river actually flowed south; today, it flows north across a flat plain, rich in topsoil left by the glacial Lake AGASSIZ. Though in time of drought (eg, 1934) the river can virtually dry up, a late spring thaw after heavy snow can cause it to spill over its shallow banks onto the plain, with disastrous effect. The flooding threat is made worse because the river flows south to north, meaning the upper reaches thaw before the lower river.
The river was discovered (1734) by the LA VÉRENDRYE expedition; a French post, Fort Maurepas, was built on the delta that year and Fort Rouge (1738) at the forks. Retired voyageurs and their Métis offspring settled along the river, but systematic farming only began with the SELKIRK colonists (1812). The river was the heart of the RED RIVER COLONY; farms were laid in narrow strips along the riverbanks for irrigation and easy transport. By 1831 enough wheat was being grown to provision part of the HBC operation. The MENNONITES (1870s) were the first to farm the prairie, away from the river. Key settlements on the river were Upper and Lower Fort Garry (seeFORT GARRY, LOWER; FORT GARRY, UPPER), Selkirk and, after 1865, the growing town of Winnipeg. The south-north course of the river encouraged commerce with the US, but this attraction lessened with the arrival of the railway from Canada. Works to prevent flooding began as early as 1844, but the major project began after the devastating flood of 1950; it drove 100 000 people from their homes and inundated 15 000 farm buildings and businesses. The Red River Floodway, a wide channel 47 km long, diverts floodwaters around Winnipeg. Other major floods occurred in 1997 and 2009. After the 1997 flood when the flood waters came close to reaching the floodway's capacity, the floodway was expanded to handle a one-in-700-year flood.
The river's name is a translation of the French Rivière Rouge (about 1740), which in turn is a translation of the Cree Miscousipi, "red water river." The river takes its red colour from the clay deep in its trench.