Region
United States
74
Alaska
52
North America
48
California
31
Wyoming
21
Colorado
20
West (U.S.)
20
Montana
19
Texas
18
Great Britain
16
New Mexico
16
Nevada
14
Utah
14
Kentucky
13
Oregon
13
Alberta
11
New York (State)
11
United States, West
11
China
10
England
10
Great Basin
10
Idaho
10
Australia
9
Europe
9
Tennessee
9
Antarctica
8
British Columbia
8
Florida
8
Marshall Islands
8
North Carolina
8
Canal Zone
7
Maine
7
Mexico
7
Nebraska
7
Panama
7
Arkansas
6
Bikini Atoll (Marshall Islands)
6
Kansas
6
Morrison Formation
6
'Eua Island
5
Africa
5
Arizona
5
Georgia
5
Maryland
5
National Petroleum Reserve (Alaska)
5
North Slope
5
Russia (Federation)
5
South Dakota
5
Southwestern States
5
Tonga
5
more ...