An Isolated continent:
North America is almost completely surrounded by water.
The Shield is rich in minerals, such as iron, gold, copper, and uranium. Most of the land is not farmable and is sparsely populated.
The Rocky Mountains:
The Rocky Mountains were formed as a result of a collision between the tectonic plate under the Pacific Ocean and the North American plate.
The longest rivers in North America are the Mississippi river in the United States and the Mackenzie River in Canada.