Colliding continents gave Blue Ridge rocks their present form and location. They did not, though, give the Blue Ridge its present appearance. Water did that. Millions of years of slow erosion carved the mountains and plateau that we know today.

The Blue Ridge of southwestern Virginia marks the second largest drainage divide in North America. It is the divide between rivers that drain toward the Atlantic and those that drain to the Gulf of Mexico. (The largest divide is the Continental Divide, the division between lands that drain to the Pacific Ocean and those that drain to the Atlantic and Gulf.)

Before the continents pulled apart, opening the Atlantic Ocean, the rivers in our region drained northward. The New River still reflects this ancient pattern that predates the rise of the Appalachian mountains. Once the Atlantic opened, however, the eastern region began draining into the Atlantic.

The Blue Ridge streams in the Atlantic drainage drop steeply and flow rapidly. They reach the Atlantic in a few hundred miles or less. Most of this drop of thousands of feet happens in the first few miles. These energetic streams carry lots of sand and gravel that cut deep stream beds and valleys. As a result, they carve their way into the Blue Ridge and back into the plateau. Over millions of years, the plateau gets smaller and smaller.

The waters of the New River, tributaries of the Tennessee River and other rivers on the plateau find their ways to the Mississippi River. They eventually reach the Gulf of Mexico after traveling about 1,500 miles. For this reason, the rivers on the Blue Ridge Plateau are much more gentle and slower moving than those draining to the Atlantic.

The Atlantic drainage is slowly "stealing" rivers from the plateau and diverting them to the Atlantic through a process called stream piracy.

Enjoying a creek

as it cascades down the ridge

toward the Atlantic Ocean