282 GEOLOGY OF THE BLACK HILLS. 



a pennyweight was obtained from one of their prospecting pits near Camp 

 Terry. Gravel deposits of considerable extent are reported in the valleys 

 of the branches of the east fork, but have not as yet been prospected by 

 the miners. The area drained by this fork is more open and less rugged 

 than the territory to the west, resembling the Elk Creek district, which it 

 adjoins. Gold has been discovered by the miners on Deadwood and White- 

 wood Creeks and the numerous gulches running into them in the vicinity 

 of Terry Peak. The placers are quite extensive, and in most places the 

 bed-rock is reported to be near the surface, and the gold is doubtless 

 derived from the disintegration and erosion of the igneous rocks as well 

 as from slates and quartzites. 



Having detected gold in similar trachytes in the Bear Lodge range, 

 I consider its occurrence in rocks of igneous origin in this district as 

 extremely probable. The following letter from Mr. T. H. Mallory, formerly 

 one of my assistants in prospecting the gold field, gives the result of his 

 explorations on the branches of Bear Butte Creek since the return of the 



expedition : 



Hill City, Dak., January 31, 1876. 



Dear Sir : Botsford and I have just returned from a trip to the north. We 

 made locations on Whitewood, a large stream that rises around the northeast side of 

 Terry Peak and runs down to the Belle Eourche. Starting from the point where the 

 creek runs into the lowlands not of the canon, forming bars, up it to the west fork, or 

 Deadwood, as it is called, there are no better paying mines for a poor man in the Hills. 

 The ground prospects in the creek and on the bars, all the way down to bed-rock, an 

 average of about two cents to the pan in fine gold. It is said to be the same on Dead- 

 wood. The length or extent of locations on these creeks begins at the mouth of White- 

 wood, and then running thence up Deadwood, makes a distance of twenty-five miles, 

 all good mining ground. 



A small gulch running into Deadwood, called Black Tail, is said to be good. 

 These mines will certainly pay from $10 to an ounce a day to the man when worked in 

 the spring. They are easily opened, for the bed-rock is not deep, like it is on Spring, 

 Castle and Bapid Creeks. 



T. H. MALLOEY. 



W. P. Jenney. 



