Region
United States
182
Mexico, Gulf of
52
Texas
39
Missouri River Watershed
38
Colorado River Watershed (Colo.-Mexico)
34
Mississippi River Watershed
13
Ohio River Watershed
13
California
11
Pacific Coast
10
Northeastern States
8
Columbia River Watershed
7
Atlantic States
6
Colorado
6
Saint Lawrence River Watershed
6
Washington (State)
6
Hudson Bay
5
Puerto Rico
5
Florida
4
Great Basin
4
Snake River Watershed (Wyo.-Wash.)
4
Southern States
4
West Virginia
4
Arkansas
3
Georgia
3
Middle West
3
Minnesota
3
Montana
3
Nevada
3
Oklahoma
3
Oregon
3
South Dakota
3
Comerío
2
Cumberland River Watershed (Ky. and Tenn.)
2
Hudson Bay Watershed
2
Illinois
2
Kansas
2
Michigan
2
New Mexico
2
Ohio
2
Pennsylvania
2
Tennessee River Watershed
2
West (U.S.)
2
Wisconsin
2
Alabama
1
Albany Region
1
Arizona
1
Bernalillo County
1
Blackstone River Watershed (Mass. and R.I.)
1
Brazos River Watershed
1
Caddo County
1
more ...