Region
United States
705
Colorado
230
California
69
Florida
39
Great Lakes (North America)
32
West (U.S.)
21
Chesapeake Bay Watershed
19
Chesapeake Bay (Md. and Va.)
17
Colorado River Watershed (Colo.-Mexico)
16
Kansas
16
Arizona
15
Long Island Sound (N.Y. and Conn.)
15
Ohio
15
Hawaii
14
Massachusetts
14
Montana
14
Louisiana
13
Oregon
13
Idaho
12
New York (State)
12
Colorado River (Colo.-Mexico)
11
North Carolina
11
Texas
11
Wisconsin
10
Alaska
9
Iowa
9
Minnesota
9
Pontchartrain, Lake, Watershed
9
Washington (D.C.)
9
New Jersey
8
Pennsylvania
8
Pontchartrain, Lake, Watershed (La.)
8
Washington (State)
8
Georgia
7
Illinois
7
Kentucky
7
Mexican-American Border Region
7
Virginia
7
Black Mesa (Navajo County and Apache County)
6
Maryland
6
Michigan
6
Utah
6
Coast Ranges
5
Delaware River Watershed (N.Y.-Del. and N.J.)
5
Everglades
5
Indiana
5
Mexico
5
Mexico, Gulf of
5
Mississippi River
5
Mississippi River Watershed
5
more ...