Columbia subject headings:
Harvard subject headings:
Recreation areas--Law and legislation--United States.
Rivers--Law and legislation--United States.
Rivers--Recreational use--United States--Information services.
Rivers--United States--Recreational use--Information services.
Water--Pollution--United States
Princeton subject headings:
Recreation areas--Law and legislation--United States.
Rivers--Law and legislation--United States.
Rivers--United States--Recreational use--Information services.
Water--Pollution--United States.