Region
United States
13
Great Britain
2
Africa, West
1
California
1
Canada
1
Colorado
1
Denver (Colo.)
1
England
1
London
1
Mars (Planet)
1
Mercury (Planet)
1
Middle East
1
Montana
1
Nebraska
1
Northern Ireland
1
Palo Alto (Calif.)
1
Philadelphia (Pa.)
1
Philadelphia County (Pa.)
1
San Juan Basin (N.M. and Colo.)
1