DRAKE, Avery A. <br/><br/>
Geology of the wood and east Calhoun mines Central city district Gilpin county, Colorado / 
by Avery A. Drake. 
 -- Washington :   United States Government Printing Office,   1957 
 - P. 130-170 + map. -- 
 (Geological Survey Bulletin  ;  1032-C).
<br/><br/><label>Subjects--Topical Terms: </label><br/>Colorado<br/>Depósitos de minerales<br/>Geología
<br/><br/><label>Universal Decimal Class. No.: </label>553(788)