Region
United States
27
West (U.S.)
13
Rocky Mountains
4
Southern States
4
Northeastern States
3
Mexico
2
Southwestern States
2
Tropics
2
Asia
1
Asia, Central
1
British Columbia
1
Canada
1
Colorado
1
Developing countries
1
Europe
1
Fraser Experimental Forest (Colo.)
1
Great Plains
1
Hawaii
1
Mexican-American Border Region
1
Middle East
1
Middle West
1
North America
1
Northwest, Pacific
1
Rocky Mountains Region
1
South Africa
1
Southwest, New
1