In the past, 
people thought of the land between the Appalachian and Rocky Mountains 
as the "middle" of the West. That is why this region is called the 
Middle West. The major landform is the Interior Plains which are made up
 of two parts. To the east are the Central Plains. To the west are the 
Great Plains. The Central Plains are not much higher than sea level in 
some places. On the western edge of the Great Plains the land is higher 
than 3,000 feet above sea level. Four of the Great Lakes are in the 
Middle West. They are Lakes Superior, Michigan, Huron, and Erie. 
Together with Lake Ontario, all five form the largest body of fresh 
water in the world.