Region
United States
52
Colorado
7
China
3
Africa
2
Burma
2
Europe
2
Leadville
2
Poland
2
Soviet Union
2
Asia
1
Brazil
1
Congo (Democratic Republic)
1
Denmark
1
England
1
France
1
India
1
Iran
1
Japan
1
Kansas
1
Lake County
1
Mexico
1
New Mexico
1
Russia
1
Shaowu Xian
1
Southwestern States
1
Washington (D.C.)
1