From American Rivers:
THE UNITED STATES HAS MORE THAN 2.9 MILLION MILES OF RIVERS.
They range from small streams and wetlands to large waterways. No two of these rivers are the same. Each river is unique to its landscape, winding through low foothills and valleys, rushing clear and cold from mountain forests, or sweeping warm and muddy down desert canyons.
ANATOMY OF A RIVER
No matter how different our rivers are, however, all rivers share some basic anatomy features.