Once a part of Mexico, Arizona now contains some of America's largest cities and lies within two principal physiographic regions of the United States. Learn about the Colorado Plateau and cites like Phoenix.
While largely desert, New Mexico occupies part of four major physical regions of the United States: the Rocky Mountains, the Great Plains, the Colorado Plateau, and the Basin and Range.
The geography of Oklahoma is dominated by rolling plains and the Ozark Mountains. Explore the landmarks, geographical features and cities of Oklahoma in this section.
Texas is the second largest state. Learn about the major cities, landmarks and geographical features in the state known as the Lone Star state.