2003 Summary of Coal Resources in Colorado Christopher J. Carroll Published: 2004 Total Pages: 36 Get eBook
Map and Directory of Permitted Colorado Coal Mines, 1981 Colorado Geological Survey Published: 1981 Total Pages: Get eBook
1990 Summary of Coal Resources in Colorado C. M. Tremain Published: 1991-01-01 Total Pages: 33 Get eBook
2003 Summary of Coal Resources in Colorado Christopher J. Carroll Published: 2004 Total Pages: 25 Get eBook