Region
United States
10
Africa
2
Asia
2
China
2
Tropics
2
Washington (State)
2
Wyoming
2
Appalachian Region
1
Arizona
1
Blue Mountains (Or. and Wash.)
1
Canada, Northern
1
Cuba
1
Eurasia
1
Florida
1
Hindu Kush-Himalayan Region
1
Illinois
1
India
1
Indonesia
1
Iran
1
Islands of the Mediterranean
1
Malaysia
1
Mediterranean Region
1
Middle Atlantic States
1
Mississippi River Valley
1
Patagonia (Argentina and Chile)
1
Pennsylvania
1
Saguaro National Park
1
Saguaro National Park (Ariz.)
1
Sierra Nevada
1
Silk Road
1
Slovakia
1
Spain
1
White River Watershed (Ark. and Mo.)
1
Yellow River
1