CHAPTER I. 



LEADVILLE— ITS POSITION, DISCOVERY, AND DEVEL- 

 OPMENT. 



Topographical description. — The city of Leadville is situated in the county 

 of Lake, State of Colorado, on the western flank of the Mosquito Range, 

 at the head of the Arkansas Valley. Its exact position is in longitude 

 106° 17' west from Greenwich and 39° 15' north latitude. Its mean 

 elevation above sea-level is 10,150 feet, taken at the court-house, in the 

 center of the city.^ 



The most striking feature in the topographical structure of the Rocky 

 jMountains in Colorado is, as is well known to those familiar with western 

 geography, the fact that it consists of two approximately parallel ridges, 

 separated by a series of broad mountain valleys or parks. 



The easternmost of these uplifts, the Colorado or Front Range, rises 

 abruptly from the Great Plains, which form its base at 5,000 to 6,000 feet 

 above the sea-level, to a crest of 13,000 to 14,000 feet. It is deeply scored 

 by narrow, tortuous gorges, worn by mountain streams, whose clear waters 

 debouch upon the plains and become absorbed in the sluggish, turbid 

 currents of the Platte and Arkansas Rivers. The trend of the range is 

 due north and south, Its highest portions being mostly included within the 



'Tlie datum point from which the levels of the map of Leadville were reckoned is the threshold 

 of the First National Bank, a stone building at the southeast corner of Harrison avenue and Chestnut 

 street. The altitude of this point, as determined by connection by levels with the bench-marks of the 

 Denver and Rio Grande Railroad, is 10,135.55 feet ; by levels with the bench-marks of the Colorado 

 Central Railroad, 10,113 feet ; by depression angles from the top of Mount Lincoln, 10,lia feet. As a 

 mean, the contour passing through it is assumed to be 10,V25 feet, greater weight being given to the 

 first figure, since the leveling by which it was arrived at was probably more carefully done than in 

 the case of the other two. A level-line had been run from Fairplay to the top of Mount Lincoln by the 

 members of the Hayden Survey in 1872. 



