Region
United States
62
Colorado
26
Alaska
22
Utah
20
Idaho
19
Nevada
19
California
18
Montana
18
Texas
14
New Mexico
13
Florida
9
Wyoming
9
Kansas
7
Washington (State)
6
Arizona
5
Canada
5
Carbon County
5
Virginia
5
Louisiana
4
North Carolina
4
Ohio
4
Oklahoma
4
Oregon
4
Vermont
4
Arkansas
3
Gilpin County
3
Mexico
3
Mineral County
3
Minnesota
3
National Petroleum Reserve
3
National Petroleum Reserve (Alaska)
3
North America
3
North Dakota
3
Pennsylvania
3
Rosebud County
3
South America
3
Sweetwater County
3
West Virginia
3
Albany County
2
Beaver County
2
Big Horn County
2
Challis National Forest
2
China
2
Clark County
2
Guerrero (State)
2
Gunnison County
2
Hardee County
2
Hillsborough County
2
Inyo County
2
Lincoln County
2
more ...