The National Wild and Scenic Rivers Act was an outgrowth of the recommendations of a Presidential commission, the
Outdoor Recreation Resources Review Commission (ORRRC). Among other things, the commission recommended that the nation protect wild rivers and scenic rivers from development that would substantially change their wild or scenic nature. The act was sponsored by Sen.
Frank Church (
Idaho) and signed into law by
Lyndon B. Johnson on October 2, 1968. A
river or river section may be designated by the
U.S. Congress or the
Secretary of the Interior. In 1968, as part of the original act, eight rivers were designated as National Wild and Scenic Rivers (
 As of July 2011 , 203 rivers, totaling 12,598 miles of river in 38 states and Puerto Rico, have wild and scenic status.
 By comparison, more than 75,000 large dams across the country have modified at least 600,000 miles, or about 17%, of American rivers.
Selected rivers in the United States are preserved for possessing outstandingly remarkable scenic, recreational, geologic, fish and wildlife, historic, cultural, or other similar values. Rivers, or sections of rivers, so designated are preserved in their free-flowing condition and are not dammed or otherwise impeded. National wild and scenic designation essentially vetoes the licensing of new hydropower projects on or directly affecting the river. It also provides very strong protection against bank and channel alterations that adversely affect river values, protects riverfront public lands from oil, gas and mineral development, and creates a federal reserved water right to protect flow-dependent values.