672 IDAHO MINING DISTRICTS. 



Volcanic rocks. A small dike of andesite occurs a short distance 

 west of Grimes Pass, and fragments of obsidian have been found in 

 Muddy Creek. 



THE VALLEY OF GRANITE CREEK. 



Configuration. Granite Creek, joining Grimes Creek 3 miles below 

 Centerville, extends from this point in a north-northwesterly direction 

 for a distance of 8 miles, heading at the low pass north of Quartz- 

 burg. A number of tributaries join it from east and west, produc- 

 ing, in the middle course of the creek, a large, basin-like depression. 

 North of Granite a narrow canyon begins. Ophir Creek, Boyles 

 Gulch, and Wolf Creek head at the relatively low divide toward the 

 Payette drainage, while Fall Creek, Trail Creek, and Canyon Creek 

 head in the Boise Ridge and carry a great deal of water. A broad 

 ridge, only 400 feet high, separates Granite Creek and Grimes Creek. 



Present stream gravels. As in the districts already described, the 

 larger part of the present stream gravels consists of tailings. They 

 are one-fourth mile wide at the junction with Grimes Creek, but only 

 a few hundred feet in width from that place to half a mile below the 

 mouth of Ophir Creek. Here they widen and attain a maximum 

 width of 1,500 feet. The tailings also reach far up on Ophir, Boyles, 

 and Wolf creeks, but narrow down to 100 feet or less a short distance 

 above Granite. Along the lower courses of Canyon Creek, Trail 

 Creek, and Clear Creek, as far as 2 or 3 miles above their mouths, are 

 stream gravels and low terraces, attaining in some places a width of 

 1,000 feet. These creeks have yielded scarcely any gold, and their 

 gravels and terraces show well the character of the river courses of 

 the basin before the gold discoveries. Clear Creek was entirely bar- 

 ren in its upper course. A little gold was found in one or two places 

 along the creek which Hawkins toll road follows from Star ranch 

 westward. Canyon Creek has produced a little gold, and Fall Creek 

 a considerable amount. The main creek has been rich from the 

 junction up to Quartzburg, while no gold is found above that town. 

 Ophir, Boyle, and Wolf creeks were very rich up to their headwaters. 

 The east fork of Alder Creek, which flows into the Payette and heads 

 opposite Wolf Creek, has also produced some placer gold. It appears 

 to be the only creek on the Payette side which is auriferous. The 

 gulches running into Ophir Creek from the east have produced 

 scarcely anything. In fact, most of the broad ridge separating Grimes 

 and Ophir creeks is singularly barren. As to the working of the 

 tailings in Granite Creek, the same remarks apply as have been 

 made in the case of the other tailings mentioned above. 



Bench gravels. Benches are found at intervals all along Granite 

 Creek as far up as half a mile above Granite; also for some distance 

 up Ophir Creek, and up Wolf Creek as far as Placerville. There are 

 usually two well-pronounced horizons, the bed rock of the lower one 



