694 IDAHO MINING DISTRICTS. 



the same porphyritic dike. The Big Six appears as a brown, much 

 decomposed vein, 1 to 2 feet wide, chiefly made up of limonite; it 

 strikes N. 55 E. and dips steeply toward the northwest, this dip being 

 an unusual one for the vicinity. The claim is developed by a small 

 shaft, and some fair assays were obtained from it, one sample contain- 

 ing $10. 33 in gold and $0. 50 in silver. The Mineral Hill group adjoins 

 on the northeast, being situated on the headwaters of Ophir Creek, at 

 an elevation of about 5,000 feet, and consists of five claims. The sur- 

 face is extremely decomposed to a brown loam, and luxuriant vege- 

 tation covers all outcrops. These claims have not yet been prospected 

 enough to determine their character, but the pay appears to be con- 

 tained in streaks in the porphyry, impregnated with pyrite and carry- 

 ing free gold on the surface at least. Near the Mineral Hill claim a 

 large extent of surface is said to contain gold. The ore is a soft, 

 decomposed rock, principally composed of limonite, one selected sample 

 of which assayed $154 in gold, $1.71 in silver. Lead carbonate also 

 occurs in the ore. Where sulphurets are found they are said to be of 

 low grade. It is probable that these deposits are similar to that of 

 the Pioneer claim, near Quartzburg. 



Claims near Grimes Pass. For 3 miles beyond the Mineral Hill 

 group, in a northeasterly direction, no mineral deposits are known, 

 though the deep soil covering the region makes it probable that no 

 thorough prospecting has ever been undertaken. About three-fourths 

 mile. west of Grimes Pass, on the summit of the ridge dividing the 

 waters of the Payette and Boise rivers, at an elevation of 5, 000 feet, 

 lie a number of claims called the Morning Star group. There are 

 eight claims laid out along two adjoining lines. The deep surface 

 soil makes prospecting difficult, and the exact character of the deposit 

 is not known. Over a large extent the surface gives good prospects, 

 and many little shafts demonstrate the presence of a considerable 

 body of low-grade free-milling ore. The ore has always the appear- 

 ance of streaks, 4 to 6 feet wide, of decomposed and brownish por- 

 phyry, striking a trifle north of east. The deposits lie in a dike, 

 several hundred feet wide, of quartz-hornblende-porphyrite, continu- 

 ing from the vicinity of Quartzburg, but the contacts of the dike with 

 the granite are difficult to trace. Samples of the ore washed in pan 

 gave good prospects of free gold, with some lead carbonate. On the 

 Morning Star a shaft 232 feet deep has been sunk. A long tunnel 

 has been started on the Payette side, 600 feet vertically below the 

 shaft, and is calculated to strike the vein 1,700 feet from the mouth. 

 In 1896 it had been driven as far as a point vertically below the shaft, 

 but work had to be suspended on account of financial difficulties. 

 Three hundred feet back from a point perpendicularly below the 

 shaft the contact of granite and porphyry was struck in the tunnel. 

 The deposits are evidently similar to those of the Pioneer mine and 

 the Mineral Hill group, and consist of a more or less shattered zone 



