Region
Colorado
18
Florida
18
California
17
United States
17
Wyoming
16
Minnesota
13
Kansas
12
Pennsylvania
12
Wisconsin
12
Oklahoma
11
Washington (State)
11
New Jersey
10
Tennessee
10
Arizona
9
Michigan
9
Nebraska
9
Nevada
9
Ohio
9
Virginia
9
Mississippi River Watershed
7
New Hampshire
7
North Carolina
7
Georgia
6
Iowa
6
New York (State)
6
Arapahoe County
5
Arkansas
5
Elbert County
5
High Plains Aquifer
5
Idaho
5
Indiana
5
Maryland
5
Massachusetts
5
Montana
5
Park County
5
Puerto Rico
5
Texas
5
Utah
5
Alabama
4
Connecticut
4
Floridan Aquifer
4
Missouri
4
Central Oklahoma Aquifer
3
Colorado River Watershed (Colo.-Mexico)
3
Denver Region
3
Great Lakes (North America)
3
Illinois
3
Lower Peninsula
3
Memphis Region
3
New Mexico
3
more ...