This river of British Columbia, Canada, begins in the Canadian Rockies near Yellowhead Pass, then flows in a variety of directions (generally south), finally turning west to empty into the Strait of Georgia, just south of Vancouver. It's (850 miles) (1,368 km) in length.
It's the longest river in Canada and dissects the Northwest Territories. It flows generally northwest into Mackenzie Bay and the Beaufort Sea. This historic river was discovered by Sir Alexander MacKenzie, and along its path are thick, green forests and dozens of major lakes. It's (1,200 miles) (1,800 km) in length. If then combined with its tributaries - the Slave, Peace and Finlay rivers - it extends to (2,635 miles) (4,240 km), and becomes the second longest river in North America, second only to the Mississippi/Missouri river system combination at (3,877 miles) (6,236 km) in length.
It is the major river of North America and the United States at (2,339 miles) (3,765 km) in length. It flows from northwestern Minnesota south to the Gulf of Mexico, just below the city of New Orleans. It is a significant transportation artery and when combined with its major tributaries (the Missouri and Ohio rivers) it becomes the third largest river system in the world at (3,877 miles) (6,236 km) in length.
It begins in southern Montana in the Rocky Mountains, first flowing north then generally southeast across the heart of the United States, ending at the Mississippi River, just to the north of St. Louis, Missouri. It is the longest river in the United States (2,500 miles) (4,023 km).