Region
United States
49
Australia
21
Great Britain
19
California
9
North America
8
Africa
6
Europe
6
Ireland
6
Alaska
5
Tropics
5
West (U.S.)
5
Canada
4
Costa Rica
4
Great Plains
4
Mexico
4
Québec (Province)
4
Washington (State)
4
Arctic regions
3
East (U.S.)
3
Italy
3
Latin America
3
Michigan
3
Russia (Federation)
3
Southern States
3
Tanzania
3
Texas
3
Amazon River Region
2
Angelina River Valley
2
Angelina River Valley (Tex.)
2
Antarctica
2
Berlin
2
China
2
Côte d'Ivoire
2
Darling River Watershed (Qld. and N.S.W.)
2
England
2
Germany
2
Hawaii
2
Himalaya Mountains Region
2
Kenya
2
Mascarene Islands
2
Mexico, Gulf of
2
Murray River Watershed (N.S.W.-S.A.)
2
Netherlands
2
New England
2
North Carolina
2
Northwest Coast of North America
2
Northwest, Pacific
2
Parc national de Taï
2
Ross Sea
2
Russian Far East
2
more ...