The Nelson River drains one of the largest watersheds in North America. Huge dams on the Nelson, built between 1957 and 1990, now turn the river's once wild and natural flow into a stream of kilowatts for the streetlights, mills, and kitchens of Manitoba. Manitoba Hydro's export customers buy the extra 'resource'. A major dam on the Saskatchewan River at Grand Rapids was completed in 1968. Northern dams account for 75% of Manitoba Hydro's total generation capacity. These dams mean that Manitoba lakes become reservoirs. Photos: Generating Stations; Kelsey, Limestone, Long Spruce, Jenpeg, Kettle, & Grand Rapids.