Region
United States
237
California
10
Caribbean Area
6
West (U.S.)
6
Japan
5
Mexico, Gulf of
4
Arctic regions
3
Mexico
3
Southwestern States
3
Africa
2
Alaska
2
Atlantic Coast (U.S.)
2
Colorado Plateau
2
Erie, Lake
2
Great Lakes (North America)
2
Middle West
2
North America
2
Northeastern States
2
Northwest, Pacific
2
Palo Alto Battlefield National Historical Park (Tex.)
2
Southern States
2
Sun
2
Arizona
1
Arkansas
1
Belize
1
Bering Sea Region
1
Bitterroot National Forest (Mont. and Idaho)
1
British Columbia
1
Canada, Western
1
Cold regions
1
Columbia River Watershed
1
Europe, Northern
1
Florida
1
Four Corners Region
1
Germany
1
Grand Canyon National Park
1
Grand Canyon National Park (Ariz.)
1
Guatemala
1
Gulf States
1
Illinois Basin
1
Islands of the Pacific
1
Klamath River Watershed (Or. and Calif.)
1
Los Angeles Metropolitan Area
1
Massachusetts
1
Mexico, North
1
Michigan
1
Michigan, Lake
1
Mississippi River Valley
1
Mississippi River Watershed
1
New England
1
more ...