Region
United States
8
Alaska
2
North Carolina
2
Aberdeen Proving Ground
1
Colorado
1
Delaware
1
Fairbanks
1
Fort Bragg
1
Green River Formation
1
Greenville
1
Harvey County
1
India
1
Kansas
1
Kentucky
1
Keyport
1
Louisville
1
Marshall County
1
Maryland
1
New Castle County
1
North Slope
1
North Slope (Alaska)
1
Ohio
1
South Carolina
1
Tennessee
1
Washington (D.C.)
1
Washington (State)
1
Wayne National Forest
1
West (U.S.)
1
Wyoming
1