미국
Yampa coal field land status and Federal mineral ownership (yamowng)
This is a shapefile and unioned polygon ownership coverage used to calculate coal resources of the A through D coal zones, Yampa coal field, northwestern Colorado. Polygons that have been combined include counties, 7.5' quadrangles, townships, surface and coal ownership. This ownership coverage was clipped by the largest resource boundary polygon--that of the A coal zone.