DENVER & RIO GRANDE WESTERN ROUTE. 



51 



miles into what is now the heart of the mountains, with isolated low 

 ranges here and there projecting above their even surface. Then 

 came a great uplift which finally raised the mountains to their present 

 positions. On this uplifted mass of rock the streams, on account of 

 their increased slope, were very active and at once began to cut deep 

 trenches ; these in time were widened where the rocks were soft, and 

 finally all the higher land on the plains was cut away, but in the 



comparatively low grade. The great 

 number of veins and the ever-present 

 possibility of finding a rich shoot at 

 some hitherto overlooljed junction of 

 inconspicuous fissures has made the 

 district a favorite field for lessees, and 

 many prizes have been won by men 

 working small blocks of ground leased 

 from their owners. The great Inde- 



pendence mine, which made a fortune 

 for Stratton and whose history consti- 

 tutes one of the romances of mining, 

 is now worked entirely by the leasing 

 system. 



The production of the Cripple Creek 

 district is shown by the following 

 table, compiled by Charles W. Hender- 

 son, of the Geological Survey: 



Gold and silver produced in the Cripple Creek district, Colo., 1891-1920. 



Formerly a considerable part of the 

 ore from the district was sent directly 

 to the smelters at Pueblo and Denver, 

 but about 9G per cent is now treated 

 in mills in the district, chiefly near 

 the town of Victor or in mills near 

 Colorado Springs. The common prac- 



tice has been roasting and cyanida- 

 tion, but in the modern Victor mill 

 of the Portland Gold Mining Co. con- 

 centration is effected by flotation and 

 the concentrates are treated by the 

 cyanide process. 



