Souris River

Souris River, about 720 km long, rises in the Yellow Grass marshes N of Weyburn, Sask, flows SE past Estevan and wanders S across the N Dakota border before entering Manitoba. Near the town of Souris it swirls through a series of deep gorges, then makes an abrupt NE turn to join the Assiniboine R. Much of its drainage basin is fertile silt and clay deposited by former glacial Lk Souris, and much of the river's course follows the cut of the lake's outfall. The river's name, French for mouse, aptly describes its meandering course, which from a distant vantage resembles the track of a mouse. The river was an ancillary route of the fur trade, and at least 7 posts were built along its gentle banks between 1785 and 1832. It is still a popular canoe route, but the dominant feature around it now is wheat.