Region
Texas
19
New Mexico
10
Utah
8
Wyoming
8
Colorado
7
Idaho
7
Kansas
7
Montana
6
California
5
Oklahoma
5
Alaska
3
Phosphoria Formation
3
White Rim Sandstone (Utah)
3
Afton Region
2
Arizona
2
Baylor County
2
Brown County
2
China
2
Coleman County
2
Cutler Formation
2
Greece
2
Hydra Island
2
Manzano Mountains
2
United States
2
Afghanistan
1
Alaska Range
1
Amador County
1
Antarctica
1
Argus Range Region
1
Brazos River Valley
1
Butte County
1
Calaveras County
1
California, Southern
1
Canyonlands National Park
1
Central Oklahoma Aquifer (Okla.)
1
Central Oklahoma Aquifer Region
1
Chinle Formation
1
Cowley County
1
Cutler Group
1
Denver Basin
1
Eagle County
1
Eagle Mountains region
1
East Tintic Mountains
1
Elk County
1
Glass Mountains
1
Gondwana (Continent)
1
Grand Canyon Region
1
Great Basin
1
Greer County
1
Guadalupe Mountains (N.M. and Tex.)
1
more ...