ECONOMIC GEOLOGY. 15 



UNDERGROUND DEVELOPMENT. 



At the time of the earlier survey the deepest shafts, those of the 

 Moose, Pharmacist, and Anna Lee mines, were down only about 400 

 feet, while few of the other mines were over 200 feet in depth. Many 

 subsequently prominent mines were then mere prospects or had not 

 been located. 



The deepest shaft at present is the Lillie, which is over 1,500 feet 

 deep, although the Stratton's Independence shaft, 1,400 feet deep, has 

 the lowest sump in the district. The American Eagle shaft is nearly 

 as deep as the Lillie, while there are about twenty other shafts over 

 1,000 feet in depth, and at least 100 shafts deeper than the deepest 

 workings existing in 1894. As regards absolute elevations, the Gold 

 Hill shafts are scarcely down to a level of 9,000 feet above sea; the 

 Elkton, El Paso, and Lillie shafts descend to 8,750 feet; Stratton's 

 Independence reaches the lowest level at 8,450 feet; while the Gold 

 Coin shaft, at 8,550 feet, is of interest from the fact that the deepest 

 ore shoot in the district is now being stoped from its twelfth level. 



The amount of drifting and crosscutting accomplished since the 

 earlier survey is more than commensurate with the increased number 

 and depth of the shafts, and the district is further intersected in vari- 

 ous directions and at different levels by two long tunnels run for 

 drainage purposes and by a dozen or more extensive adits, many of 

 which have their portals in the granitic rocks and extend well into the 

 central part of the breccia area. 



BRIEF REVIEW OF THE MINES. 



The productive district, as stated above, is practically covered by the 

 area of a circle 3i miles in diameter. The center of this circle would be 

 located halfway between Raven Hill and Bull Hill, and the towns of 

 Cripple Creek, Victor, and Cameron would be situated on its peripheiy . 

 A very few mines notably the Galena and the Fluorine and many 

 prospects lie outside of this area. 



The culminating points of the district are found in a ridge of higji 

 and bare hills that extends in a northwest-southeast direction and 

 divides the waters flowing into Cripple Creek and Wilson Creek on the 

 southwest from those joining Spring Creek and Grassy Creek on the 

 north. From northwest to southeast the following hills mark this 

 divide: Mineral Hill, Carbonate Hill, and Tenderfoot Hill, north 

 or northeast of Cripple Creek; Globe Hill, Ironclad Hill, and Bull 

 Hill, the latter being near the center of the district and equidistant 

 from Cripple Creek and Victor; the ridge is continued by Bull Cliff 

 and Big Bull Mountain, the latter, really outside of the productive 

 area, being the highest point in this dividing range of hills. Its ele- 

 vation is 10,826 feet. Three long spurs project to the southwest from 



