Spatial Coverage
- Barton County (Kan.)2
- British Columbia2
- Canada2
- Cripple Creek2
- Cripple Creek Mining District (Colo.)2
- Ellis County (Kan.)2
- England2
- Estonia2
- London (England)2
- Maryland2
- Middle Atlantic States2
- Nevada2
- New Jersey2
- Oregon2
- Osborne County (Kan.)2
- Pennsylvania2
- Rhode Island2
- Smoky Hill River (Colo. and Kan.)2
- South Africa2
- South Carolina2
