16 University Geological Survey of Kansas. 
‘““The great lead-ore bodies of the far West are of com- 
paratively recent development, none being generally known 
forty years ago. 
‘*In Utah, the Mormons claim to have mined the silver-lead 
ores of Beaver county in 1861; those of Bingham canon were 
opened in 1863. The deposits of the Cottonwood district, in- 
cluding the Emma, were discovered in 1864; the Emma mine 
was not opened until 1870, however, and was abandoned in 
1875. The Horn Silver deposit was discovered in the latter 
year. 
‘‘TIn Nevada, the Lander county deposits were discovered as 
early as 1862; the Hureka deposits soon after, in 1864, but 
their value was not determined until 1870. Those of Lincoln 
county were also discovered in 1864, of Esmerelda county in 
1867, and of the White River district in 1869. 
‘‘In Montana, the argentiferous galena of Jefferson county 
was known before 1865, and smelters were soon after 
erected. Because of difficulties of transportation, however, 
much ore was not smelted for some ten years. 
‘“‘The Colorado lead and silver deposits at Georgetown 
were worked in 1866, but the great carbonate deposits at 
Leadville were not discovered until 1874, and mining was 
not well under way there until 1876. The Aspen deposits 
were developed about 1882. 
‘‘TIn Idaho, argentiferous galena was discovered near Idaho 
City as early as 1867, the South Mountain deposits about 
1871, the Wood river in 1873, and the Cceur d’Alene within 
the past ten years. 
‘‘In South Dakota, most of the little lead mining done has 
been during the last decade. 
‘““ZInc Mintna.—The association of zinc ores with the 
lead ores of many of the deposits of the United States, both 
in the Kast and the West, led necessarily to this mining 
along with the latter ores. ‘To the majority of miners zinc 
compounds were probably unknown and hence not recog- 
nized. It is probable, however, that their existence in the 
country was known before the beginning of the present cen- 
tury. The earliest reference to such ore in the Mississippi 
