200 GEOLOGICAL SUEVEY OF THE TEREITOEIES. 



Gold. In placer-mines, Alder Gnlcb, Madison County, Montana Ter- 

 ritory ; in various mines about Virginia City ; in a jaspery ore at 

 Eed Bluff lode, Hot Spring district, Madison County, Montana Ter- 

 ritory ; in Emigrant Gulch, opposite Botteler's Eauch, on Yellow- 

 stone Eiver, Montana Territory ; in mountains along the Jefferson 

 Eiver, Jefferson County, Montana Territory. 



Halite, (common salt). In cold springs on Turbid Lake, near Yellow- 

 stone Lake ; in springs near Evanston, Utah ; in springs in Idaho. 



Hauynite. In phonolite, in Pleasant Valley, Idaho Territory. 



Hornblende. In syenites at Ogdeu, Utah Territory ; in hornblende 

 schists below Virginia City, Montana Territory ; in gneissic rocks on 

 tbe Madison Eiver above Virginia City ; in gneissic rocks in the 

 caSon of the Yellowstone Eiver above JBotteler's ; in acicular crj^s- 

 tals in trachyte on the summit of Mount Washburne, near the Great 

 Falls of the Yellowstone ; in the same form in trachytic rocks on top 

 of Mount Stevenson, near Yellowstone Lake; in a red volcanic rock 

 witli calcite at Promontory Point, Yellow^stone Lake. 



Jasper. Eed variety associated with blue chalcedony and opal at Eed 

 Bluff* lode, Montana Territory ; green variety on south branch of the 

 East Fork of Yellow^stone Eiver. 



Leucite. In volcanic rocks near Yellowstone Lake. 



Malachite, (green carbonate of copper.) Wild Cat Canon, Montana 

 Territory; near Virginia City, Montana Territory; witli chalcedony 

 near Mount Washburne. 



Minium, (red oxide of lead.) Near Virginia City, Montana Territory. 



Nephelite, (var. sommite.) In i3honolite at Pleasant Valley, Idaho 

 Territory. 



Opal. Wood-opal at tbe southeast arm of Yellowstone Lake ; beauti- 

 ful black and white specimens from Jefferson County, Montana Ter- 

 ritory. Semi-opal in center of quartz geodes on the south branch of 

 the East Fork of Yellowstone Eiver. Dendritic at Eed Bluff' lode. Hot 

 Spring district, Madison County, Montana Territory. Geyserite in 

 the geyser-basins of Fire-Hole Eiver. 



Obsidian, (volcanic glass.) In chips along the Port Neuf Eiver, in vol- 

 canic rock ; in the valley of the Yellowstone Eiver in chips ; in vol- 

 canic rocks in the Grand Cation of the Yellowstone ; massive in the 

 mountain ridge between Yellowstone Lake and the Fire-Hole Eiver; 

 porphyritic near Madison Lake. 



Pumice. Emigrant Gulch opi^osite Botteler's ; near Yellowstone 

 Lake. 



Quartz. In granites throughout the Eocky Mountains; in geodes, 

 with chalcedony, near Gardiner's Eiver ; in geodes on south branch 

 of East Fork of Yellowstone Eiver; crystals near Virginia City. Mon- 

 tana Territory. 



Serpentine, (compact resinous.) In Alder Gulch, near Virginia City, 

 Montana Territory. 



SiLiciFiED Wood. At Tower Creek at the foot of Tower Falls; near 

 White Hot Springs at Gardiner's Eiver ; on the southeast shore of 

 Y^ellowstone Lake. Handsome black specimens, with veins of blue 

 chalcedony, on the south branch of the East Fork of Yellowstone 

 Eiver, in Jefferson County, Montana Territory. 



Silver. Native and as chloride, in various mines about Virginia City ; 

 near Oxford, Idaho Territory ; in galena, throughout Utah, Idaho, 

 and Montana Territories. 



Spherulite. At the Grand Caiion of the Yellowstone River ; at the 

 southern end of Yellowstone Lake. 



