Rio Grande forms the Southern border of the United states.
rio grande
rio grande
The Rio Grande forms the border between Mexico and the United States.
Columbia
Rio grande
The Colorado River forms the border between Arizona and California.The Colorado River.
the answer is colorado river
The St. Lawrence River forms part of the eastern end of the border between Canada and the United States. The St. Lawrence River is also used as a shipping channel. Ships use it to go between the Atlantic Ocean and the Great Lakes.
The Mississippi River forms the western border of Illinois. It spans approximately 580 miles and flows through or along the borders of 10 different states in the United States.
The Columbia River forms a border between the states of Washington and Oregon.
There are no rivers in the southeastern United States that flow in the Pacific Ocean. However, the Columbia River forms a portion of the border between Washington and Oregon and flows into the Pacific Ocean.