Region
Canada
United States
31
Australia
3
Great Britain
3
Denmark
2
Mexico
2
New Zealand
2
Norway
2
Sweden
2
Arctic regions
1
Finland
1
Great Lakes (North America)
1
Great Lakes Watershed (North America)
1
Iceland
1
Italy
1
Netherlands
1
North Dakota
1
Russia (Federation)
1
Saint Lawrence Seaway
1
Saskatchewan
1
Souris River Watershed
1
Tropics
1
Turkey
1
Ukraine
1