Numerous schemes were suggested in the 1960s to accomplish large-scale water transfers between major basins in North America, and one of the best known is the North American Water and Power Alliance (NAWAPA). The plan was devised by the Ralph M. Parson Company of Los Angeles "to divert 36 trillion gallons of water (per year) from the Yukon River in Alaska (through the Great Bear and Great Slave Lakes) southward to 33 states, seven Canadian provinces, and northern Mexico."

The proposed NAWAPA system would bring water in immense quantities from western Canada and Alaska through the plains and desert states all the way down to the Rio Grande watershed and into the Northern Sonora and Chihuahua provinces of Mexico. The Rocky Mountain Trench, Peace River, Great Slave Lake, Lesser Slave Lake, North Saskatchewan River, Columbia River, Lake Winnipeg, Hudson River...