The Interior Highlands

Two separate highlands regions rise above the plains in the central United States. These are the Superior Highlands and the Ozark Plateau. Located around Lake Superior, in the northern parts of Minnesota, Wisconsin, and Michigan, the Superior Highlands are actually a part of the Canadian Shield. Coniferous forests cover rocky plateaus. There are many lakes among the hills.

The Ozark Plateau is located between the Missouri and Arkansas rivers west of the Mississippi River. The land is gently rolling in places with some rugged mountains in other places.

The Rocky Mountains

West of the Great Plains is the Rocky Mountain region. The Rocky Mountains extend from Canada south to New Mexico and Western Texas. The region occupies an area over 1600 kilometers long. It varies in width between 200 to 600 kilometers.

Like the Appalachian Mountains the Rockies stretch from north to south. The Rocky Mountains, however, are much more rugged and much higher than the Appalachians.

Many peaks are over 3,658 meters high. Plants are greatly affected by altitude. Broadleaf deciduous trees are found at lower elevations with needleleaf conifers higher up.

Mountain tops not covered by snow are capped by tundra grasses and mosses.