IS-68 Directory of Active Mines and Mine Permits in Colorado IS-68 Directory of Active Mines and Mine Permits in Colorado, 2002
IS-45 Active Permitted Mine Operations in Colorado IS-45 Active Permitted Mine Operations in Colorado, 1996-1997
IS-41 Active Permitted Mine Operations in Colorado IS-41 Active Permitted Mine Operations in Colorado, 1995-96
OF-75-02 Selected References on Colorado Mineral Resources OF-75-02 Selected References on Colorado Mineral Resources