Spatial Coverage
- Pennsylvania10
- U.S.10
- Emery County9
- Powder River Basin (Wyo. and Mont.)9
- Sandoval County.9
- Powder River County8
- Powder River County (Mont.)8
- Sheridan County8
- Colchester (County)7
- Colchester (N.S. : County)7
- Cumberland (County)7
- Cumberland (N.S. : County)7
- Kane County7
- McKinley County (N.M.)7
- Sheridan County (Wyo.)7
- Carbon County6
- Garfield County6
- Schuylkill County6
- Indiana5
- Jackson County5
