The Souris River originates near Weyburn, Saskatchewan, and flows generally eastward before eventually crossing into Manitoba. In Saskatchewan, the river passes through the city of Weyburn, where the City maintains a floating portable dock in River Park that serves as a launch point for canoes and kayaks. Jurisdiction over the river rests with the Crown rather than the City of Weyburn, and paddlers assume all risk and liability when using the river.

Further downstream, the Souris River feeds Rafferty Reservoir, a substantial body of water nearly 40 miles in length located between Weyburn and Estevan. Rafferty has a public boat launch with a concrete ramp and two docks at Rafferty Marina, though the marina is not developed and does not offer slips for continuous mooring. Camping near the marina is available in a gravel parking lot or nearby pastureland, without electrical or water hookups. The reservoir's summer operating level is maintained at 549.5 meters, with maximum storage capacity at 554 meters.

Rafferty Reservoir supports populations of walleye, pike, and perch, which have reportedly grown in recent years alongside increased aquatic vegetation. Rocky outcroppings are a notable geographical feature of the terrain surrounding the reservoir. The Souris River's headwaters begin approximately 140 river miles from Estevan, giving the Saskatchewan portion of the river considerable length before it reaches the reservoir.

Paddlers using the Souris River in winter or on ice surfaces are reminded by the City of Weyburn that users assume all risk, and standard ice thickness guidelines apply: a minimum of 10 cm for foot travel and 20 cm for snowmobile or ATV use.