226 GEOLOGICAL SURVEY OF THE TEREITOEIES, 



There appear to be two series of veins in this great mineral belt, oc- 

 curring at least along the eastern slope of the Eocky Mountains ; the 

 larger, and apparently elder, having a general north and south strike, 

 and proving in most cases barren,* and the smaller and more recent, 

 comprising by far the greater number of the gold and silver leads, and 

 extending down the range as far as 1 had an opportunity of observing 

 it, in ISTew Mexico, striking generally about northeast and southwest. 



It would be diificult to deiine sharply the direction or extent of this 

 great mineral belt, though various writers on Colorado have indulged in 

 fine generalizations on the subject. The fact appears to be that circum- 

 stances have been more favorable to the existence of mineral veins in 

 some rocks than in others, and that whatever may have been the great 

 geological causes which brought these rocks into being, where the con- 

 ditions are not totally different, indications of the precious metals may 

 be expected wherever they occur. The eastern boundary of this belt is 

 in general terms the eastern boundary of the gneissic and granitic rocks 

 of the Eocky Mountains, but in almost every instance where outliers ot 

 these same rocks occur, investigation has proved the existence of min- 

 eral veins : (e. g., Pike's Peak, which lies 150 miles east of the main chaid 

 of the Eocky Mountains, the San Lazaro Mountains, the Cerillos, in 

 the valley of the Gallisteo, &c.) 



The first lode was discovered in Colorado by John Gregory, May 6, 

 1859, on claim 'No. 5, of what is yet called the " Gregory lode," near 

 Central City. The history of that discovery is very interesting, as an 

 illustration of what energy and perseverance, guided by sound common 

 sense, may accomplish for a man. 



"Gregory worked this lode at first, of course, with a sluice, and got out 

 $972 from the disintegrated surface. The news spread rapidly, and the 

 country was soon swarming with ^prospectors and miners, and many 

 other lodes were immediately discovered and worked. This was the 

 celebrated Pike's Peak gold fever, from which the growth of this Terri- 

 tory dates. In almost every case the mines passed into the hands of 

 different parties, as the getting out and treatment of the ore became 

 more difficult from the growing scarcity of the decomposed surface ore, 

 until at last matters were brought to a stand- still by the resistance 

 oifered by the sulphurets associated below with the gold to the process of 

 amalgamation then in vogue. This behavior, which would have been 

 foreseen by more experienced miners, seems to have astonished and dis- 

 pirited them, and an exodus from the region was the result, which has 

 been repeated at various times since, whenever new obstacles were to be 

 surmounted. But while this has retarded the unnaturally rapid develop- 

 ment of the Territory, there is no doubt that the occurrence of these sul- 

 phurets and the working of them will, in the end, prove a blessing to 

 Colorado, by giving employment to more persons, and thus hastening 

 the maturity of this commonwealth. 



The counties of Colorado in which as yet the principal mining opera- 

 tions have been conducted, are, in the order of their present importance : 

 Gilpin, Clear Creek, Park, Summit, Lake, and Boulder. 



To enumerate all the lodes which have been discovered, or even those 

 that" have been partially wrought, would be foreign to the purpose of 

 this report, and a work of immense labor ; nor would such a catalogue 

 serve the statistician as much as might at first appear, for the object of 

 all these incipient undertakings having been to realize the greatest pos- 



* An exception to this general rule is found in tlie Hoosier lode, about forty miles 

 north of Central City. This vein belongs to the north and south class, but is never- 

 theless rich and iirohtable. 



