Columbia subject headings:
Allegheny River (Pa. and N.Y.)
Mississippi River--Description and travel.
Mississippi River--Navigation.
Monongahela River (W. Va. and Pa.)
Ohio River--Description and travel.
Ohio River--Navigation.
Harvard subject headings:
Allegheny River (Pa. and N.Y.)--Description and travel.
Allegheny River (Pa. and N.Y.)--Navigation.
Inland navigation--United States.
Mississippi River--Description and travel.
Mississippi River--Navigation
Monongahela River (W. Va. and Pa.)--Description and travel.
Monongahela River (W. Va. and Pa.)--Navigation.
Ohio River--Description and travel.
Ohio River--Navigation.
Pilot guides--United States.
Princeton subject headings:
Allegheny River.
Mississippi River--Description and travel.
Mississippi River--Navigation.
Monongahela River (W. Va. and Pa.)
Ohio River--Description and travel.
Ohio River--Navigation.