The Midwest

The American heartland stretches across the central United States from Ohio and the Great Lakes almost to the foothills of the Rocky Mountains. Several times in the last Ice Age giant glaciers flowed south from Canada across this gentle land, scooping out thousand of lakes in Minnesota, Wisconsin, and Michigan. Of these, the Great Lakes form the world’s largest body of fresh water. Farther south, the ice sheets melted into countless streams that carried crushed rock and fine silt that account for the rolling hills and fertile prairie soils found throughout the lower Midwest.

There are giant rivers, too. The Ohio, Missouri, and a dozen other large rivers join the Mississippi to become the longest and most important river system in North America. Farther west in the Dakotas, sediments from rivers and ancient oceans have eroded into bizarre landforms called badlands. Nearby, the Black Hills rise above the Great Plains.

The Southwest

Diverse landscapes and sunny weather characterize the American Southwest. Deep canyons dominate the Colorado Plateau west of the Rockies, where the Colorado River winds through Arizona’s Grand Canyon. Dams and reservoirs now tame this once mighty waterway, which provides water and power to cities and farms. South of the plateau the Sonoran Desert stretches into Mexico. The silt-laden Rio Grande flows out of the Rocky Mountains, carrying snowmelt to thirsty lands along the Texas-Mexico border.

The windswept Great Plains stretch east of the Rockies across mostly level Texas and Oklahoma. Rivers move southeast through this short-grass prairie to the coastal plain, then empty into the Gulf of Mexico. Like the land, the climate changes with location. Precipitation is scarce except in the eastern part of the region. Southwestern winters can be cold and snowy, but summers are hot and sunny.