12 



BULLETIN 131, UNITED STATES NATIONAL MUSEUM 



Ada County 



1. Black Hornet (Highland Valley, Shaw Mtn.) Au, Ag (D., PL). 

 8 miles east of Boise, O. S. L. R. R. 

 Granite cut by granite-porphyry. 

 Veins. 

 Lindgren, W., The mining districts of Idaho Basin and Boise Ridge, Idaho. 



18th Ann. Rept., pt. 3, 1898, pp. 703, 705, 707. 

 Min. Res. 1905, pp. 224-225. 



1906, pp. 249-250. 



1907, pp. 288-289, pt. 1. 



1908, pp. 414, pt. 1. 



1909, pp. 431, pt. 1. 

 Top sheet Boise. 



Folio 45, 1898. 



In the first line are given the three names by which the district is 

 known. The abbreviations Au and Ag are chemical symbols indi- 

 cating that gold and silver are the metals mined in the district, gold, 

 mentioned first, being the more important. The abbreviations D 

 and PI. in parenthesis indicate that both deep mines and placers are 

 worked, the deep mines, mentioned first, being the most important. 

 The second line gives the location of the district with reference to 

 the nearest railroad point — 8 miles east of Boise station on the 

 Oregon Short Line Railroad. The next line states that the inclosing 

 rocks are granite cut by granite porphyry and the fourth line that 

 the deposits of the deep mines are veins. The references are to the 

 third part of the Annual Report of the United States Geological 

 Survey for 1898 and to several volumes of the series of reports of the 

 United States Geological Survey on the Mineral Resources of the 

 United States. Finally the last two lines indicate that the district 

 is within the area covered by the topographic map of the Boise quad- 

 rangle and by geologic folio No. 45, both published by the United 

 States Geological Survey. 



The abbreviations used for the metals mined are as follows: 



Black Hornet (Highland Valley, Shaw Mountain). 



east of Boise, O. S. L. R. R. 

 Granite cut by granite porphyry. 



Veins. 



Au, Ag (D, PL), Smiles 



