4 GEOLOGY OF THE BLACK HILLS. 



graph on the paleontology of the region, with illustrations of many new 

 and characteristic forms. 



The mineral resources of the country, for the examination of which 

 the expedition was primarily organized, are not great!}?- varied in character. 

 The deposits of auriferous gravels, found in many parts of the Hills, pro- 

 duced "prospects" sufficient to attract a large influx of miners; and it is 

 probable that many of the districts will pay a fair remuneration for labor 

 and outlay. Reports on the discoveries made during the summer were 

 transmitted from time to time to the department, and fuller accounts, with 

 analyses since made, will be found in the chapter on Economic Geology. 

 This chapter, from its immediate importance, was published by resolution 

 of the Senate, April 18, 1876, in advance of the rest of the report, being 

 accompanied by a description of the climate and general resources of the 

 Hills and by a small preliminary map.* 



The portion of the Black Hills east of the meridian of 10i° lies within 

 the permanent reservation set aside for the different tribes of the Dakota 

 or Sioux Indians by the provisions of the treaty of 1858. According to the 

 terms of this treaty the reservation is bounded "on the south by the north 

 line of Nebraska, latitude 43°; on the west by the boundary between Wy- 

 oming and Dakota, longitude 104° west; on the north by the parallel of 

 latitude 46° north, and on the east by low water on the Missouri River," alto- 

 gether embracing an area of about 40,570 square miles. Beside this area, 

 by the same treaty, all the country north of the North Platte and east of 

 the summits of the Bighorn Mountains, is held as unceded Indian terri- 

 tory, practically granted to them as a hunting reservation. By special 

 agreement, however, made in 1875, the right of the Indians to hunt in 

 Nebraska, south of the Niobrara and west of the 100th meridian, was relin- 

 quished for the sum of 825,000. 



This large reservation, excepting the Black Hills, their immediate 

 vicinity, and the narrow valleys of some of the more important streams, is 

 a most inhospitable region, desolate and barren, and includes a large area 

 of the well-known sterile and clayey tracts of " bad lands." Once abound- 



* Forty-fourth Congress, first session, Senate Ex. Doc. No. 51. The Mineral Wealth, Climate and 

 Rainfall, and Natural Resources of the Black Hills of Dakota, hy Walter P. Jenney, E. M., Geologist in 

 charge. Washington, 1876. 



