What river forms a border between the United States and parts of Mexico?
What geographic region is located along the Atlantic Ocean and the Gulf of Mexico?
What geographic region is located west of the Rocky Mountains and east of the Sierra Nevadas?
What geographic region may be described as “Rugged mountains along the Pacific Coast that contain fertile valleys”?
What river was the gateway to the west?
On a map of North America, which of the following rivers would be farthest east?
What river was explored by Lewis and Clark?
What geographic region contains the oldest mountain range in North America?
What river was explored by the Spanish?
What geographic region consists of flat lands that gradually increase in elevation westward?
What water feature provided the French and Spanish with exploration routes to Mexico and other parts of America?
Where is the Continental Divide located?