GEOLOGICAL SUEVEY OF THE TEERITOEIES. 143 



kind, will probably never be found in abundance. The mountains on 

 the west side of the Jefferson are lower than those on the east side, 

 a much wider range, and far less rugged in outline. The Carboniferous 

 limestones occur only in restricted patches. The metamorphic group 

 is exposed fully, with here and there an outburst, of the trachyte basalt. 

 All the little streams, as laid down on the map, cut deep channels from 

 the summit to the valley of the Jefferson, and are now or have been 

 filled with miners searching for gold. 



The mountains on the west side of Table Mountain and those at the 

 Bources of Fish Creek are gneissic and contain valuable mines of gold. 

 The limestone range on the east side of the Jefferson is cut off by the river 

 temporarily, at the bend where White-Tail Deer and Pipestone Creeks 

 enter it ; but it commences again on the opposite side and extends far 

 northward. The Jefferson Valley is from five to eight miles wide and 

 of oval shape, narrowing to a caiion at either end. The east range 

 trends about northwest and southeast, while the limestones on the west 

 side dip southwest. They appear to rise vertically out of the valley 

 plain, as if the whole range had either been carried up vertically in a 

 narrow belt, or that it was caused by depression and elevation ; that as 

 the range arose the valley was depressed, producing this abrupt flexture 

 in the limestone strata. At Silver Star the metamorphic group comes 

 in close to the Jefferson on the west side, and continues far up for 

 several miles. The strata incline southeast and extend across the 

 mountains and hills in long and quite regular lines. There are here 

 two important gold lodes, " Iron Eod " and " Green Campbell." The 

 latter is seven to ten feet wide, with quartz that pays well. It has been 

 wrought for three years with success. 



Just north of " Silver Star " there are some patches of limestone that 

 extend up almost to the summit of the range. This range of mountains 

 lies between Deer Lodge Valley and that of the Jefferson ; and although 

 the rocks are mostly metamorphic, yet there are remnants enough of 

 the Carboniferous limestone to show that it formerly extended over the 

 area occupied by the mountains. The elevation of this granitoid range 

 is not as great as the limestone range on the east side. It will average 

 from 800 to 1,500 feet above the valley, some of the peaks reaching 

 1,000 to 1,500 feet above the bed of the Jefferson. About three miles 

 below the forks of Beaver Head and Big-Hole Elvers, the Stinking 

 Water comes in from the southeast and forms a sort of breach in the 

 limestone range. The latter turns off to the southeast, the limestones 

 cease entirely, and the numerous little branches of the Stinking Water 

 cut deep into the metamorphic strata, forming good mining gulches. 

 On the west side of the Stinking Water the high limestones continue 

 northward to the sources of Stinking Water and Black -Tail Deer Creek, 

 where they were studied, by us on our journey to Virginia City in June. 

 The valley of the Stinking Water is from four to six miles in width, and 

 extends up to the canon, in full view of the Jefferson Valley, so that 

 our two belts of explorations connect from time to time. 



Beaver Head Eock is Carboniferous limestone, with a dip 23° southwest. 

 It seems to be a jiortion of a ridge extending across the valley from the 

 Stinking Water Eange. The Beaver Head Fork cuts a narrow channel 

 through it, forming a sort of caiion, with limestone walls on either side. 

 Passing Beaver Head Eock, the strata, which are well shown for miles along 

 the west side of the Beaver Head Fork, seem to incline southwest ; and 

 I have no doubt from the style of surfoce weathering that beds of more 

 modern date, Jurassic or Cretaceous, appear soon on the summits of the 

 mountain hills. Around Bannock City, about twelve or fifteen miles 



