Drainage:
1. Many rivers flow across this land and some of them following the valleys are formed by the glaciers.
2. The Mississippi and Missouri rivers are the longest rivers in North America.
3. The Mackenzie River is the second largest drainage basin of North America. It has it source from Great Slave Lake and drains into Arctic Ocean.
4. St. Lawrence has its origin in Lake Ontario which flows north east and drains into the Atlantic Ocean.
5. The plateau of the west has been cut deeply by the River Columbia and its tributary which forms many gorges called Canyons.
6. The most famous is the Grand Canyon cut by the River Colorado which all flows over the plateau of Columbia.
7. The River Yukon rising in the north-west of the Western mountain system is frozen for eight months in the year.
8. The River Rio Grande flows into the Gulf of Mexico and forms the boundary between USA and Mexico.
9. The most important chain consists of five lakes. The biggest is Lake Superior and it is the largest freshwater lake in the world.
10. Lake Winnipeg, Great Bear Lake and Lake Athabasca are some of the other lakes in Canada..
