Region
United States
279
Colorado
100
Texas
64
California
60
Missouri River Watershed
55
Colorado River Watershed (Colo.-Mexico)
53
Florida
52
Mexico, Gulf of
52
Kansas
48
Minnesota
44
Oregon
44
Washington (State)
44
Wisconsin
44
Mississippi River Watershed
42
Pennsylvania
35
North Carolina
29
Ohio
29
Missouri
28
New York (State)
27
New Jersey
26
Utah
24
Nebraska
22
Wyoming
22
Arizona
21
Massachusetts
21
Illinois
20
Arkansas
19
Oklahoma
19
Virginia
18
Georgia
17
Michigan
17
New Mexico
16
Connecticut
15
Indiana
15
Nevada
15
South Dakota
15
Ohio River Watershed
14
South Carolina
14
Alabama
12
Iowa
12
Kentucky
12
Southern States
12
Montana
11
Maryland
10
Pacific Coast
10
Illinois River Watershed
9
Northeastern States
9
Tennessee River Watershed
9
Alaska
8
Columbia River Watershed
8
more ...