190 GEOLO(^ICAL SURVEY OF THE TEEEITORIES. 



Near us there were two vents, from wMcli the steam, in escaping, made 

 a noise exactly like -a large steamboat letting off steam. The volume of 

 steam was very large, and the discharge constant. There were here also 

 some small mud- springs. Every night while at this place we experienced 

 earthquake-shocks, each lasting from five to twenty seconds. We named 

 it Earthquake Camp. A few hundred yards back of us there is a small 

 group of mud-springs, in which" the mud was of a pure white color. 

 About two miles northeast of the lake we discovered a small lake, which 

 was named Turbid Lake, from the muddiness of its water. It tasted of 

 alum, and- there seemed to be numerous springs throughout it, as there 

 was a bubbling all over its surface. On its eastern shore there was a 

 group of hot springs, mud-springs, and vents. The largest spring was 

 situated in the midst of a small stream flowing into the lake, and had a 

 temperature of 186° P. On the side of a small hill, at whose base the 

 principal mud-springs were situated, there was an abundant deposit of 

 sulphur and alum. In some places the mud had become quite compact, 

 and upon being broken revealed the presence of sulphur runniug through 

 it in veins. Almost all these springs gave off sulphureted hydrogen gas. 

 The temperatures varied from 176° E. to 192^ E. A short distance north 

 of this group there were some large mud-springs, one of which was 

 white and another black. The latter had a large quantity of sulphur 

 in its composition. On the northern shore of the lake there are four or 

 five cold springs, containing chloride of sodium. This place is used by 

 the deer and elk as a lick. Our horses recognized the presence of salt 

 at once, and licked the ground with avidity. Nearly all the springs 

 near the Yellowstone Lake seem to have passed their most energetic 

 stage, and are now on the decline. 



On the 23d of August we left Yellowstone Lake, and, taking a north- 

 easterly direction, started on our way toward the East Eork of the Yel- 

 lowstone Eiver. The first part of our route was along Pelican Creek, 

 one of the tributaries of the lake, which we followed to its source, cross- 

 ing the divide between it and the branches of the East Eork, toward 

 evening, when we camped at the shore of a beautiful little lake in the 

 woods. The valley of Pelican Creek is quite wide, and the stream flows 

 through it in a serpentine manner, its waters covered with wild ducks 

 and geese. There were a number of springs scattered along its banks, 

 the majority of them cold. One, however, had a temperature of 66° P. 

 There were a few geyser-cones, although as geysers they are probably 

 now extinct. We reached the southern branch of the East Fork the fol- 

 lowing evening, after a day of hard travel through the dense pine forests 

 and up and down steep mountains, and camped, a few miles above the 

 junction of the north and south branches, in a wide open valley. In 

 the bed of the stream I obtained good specimens of agate, quartz, and 

 chalcedony. Some were in the form of geodes, and contained opal in 

 the center. I also obtained black flint, green jasper, and excellent 

 pieces of silicified wood, some of which were of a jet-black color, hadng 

 veins of blue chalcedony running through it. About three miles from 

 our camp, on the north branch of the East Fork was a large mound of 

 hot-spring formation, consisting chiefly of calcareous material resem- 

 bling very much the formation at Gardiner's Eiver. It is conical, about 

 20 feet high, and 25 feet in diameter at its base. It is situated on one 

 end of a sort of i^latform, of the same material, which is 75 feet long, 

 and rises 15 feet above the surrounding level. It is probably an ex- 

 tinct geyser, although now there is no water in it, nor is there any hot 

 spring near. There is, however, a cold spring near it, in which the 

 water had an acid reaction, tasting strongly of Iron alum, of which there 



