The Salmon River in Idaho, one of the longest free-flowing rivers in the United States, rushes through a geologic wonderland of wooded ridges, eroded bluffs, and stone towers and crags.
As they prepare for a satellite that will measure the height and areal extent of rivers in unprecedented detail, hydrologists have released a better map of North American river widths.
The Green River in eastern Utah once carved soft sediment into meanders on a floodplain. Then the land and mountains rose and the river dug deep, preserving those meanders in stone.
Acquired April 2, 2011, and February 27, 2011, these natural-color images show rising waters on the Kuiseb River, which flowed all the way to the Atlantic Ocean for the first time in decades.
This photo-like image shows extensive flooding on the Red River near Fargo, North Dakota, on March 28, 2009 as the river reached a record high of 40.82 feet.
Meandering across a wide, relatively flat plain, the White River of Arkansas is no stranger to flooding. With regularity, spring rains push the river over its banks, inundating the flood-adapted forest that surrounds it. The river reached its fifth highest crest of 33.78 feet on April 19, 2008.
Black Canyon of the Gunnison National Park is a small park that encompasses the steep-walled canyons of the Gunnison River, which drains snowmelt from the Rocky Mountains in western Colorado.
This false-color image from April 1, 2002, shows numerous braided channels and oxbow lakes along the Songhua River in northeastern China, just upstream of the city of Harbin.