300 EEPOET UNITED STATES GEOLOGICAL SURVEY. 



CHAPTEE XII. 



HOT SPRINGS OF LEWIS LAKE AND SNAKE EIVEE. 



In this chapter I will refer briefly to several comparatively unimpor- 

 tant spring areas which were not examined in detail by us in 1878, but 

 ought to be described here for the sake of completeness. If the south- 

 ern boundary of the Park should be changed to a line farther north, as 

 has been proposed,* the springs on Snake Eiver which are described in 

 this chapter would be outside the limits of the Park. 



The Snake River Springs were passed in 1863 by the prospecting 

 party with which Captain De Lacy was connected, and they are men- 

 tioned by him on page 128 of the Contributions to the Historical Soci- 

 ety of Montana, Yol. I. In 1872 the Snake Eiver Division of the United 

 States Geological Survey visited them, and the descriptions given in 

 this chapter are from the descriptions of members of that party. 



The geology of the localities in which the springs here described are 

 situated does not differ from that of the Heart Lake and Shoshone 

 Basins. 



HOT SPRINGS OF LEWIS LAKE. 



The springs on Lake Lewis were not visited by us, and the following 

 account of them is taken from Professor Bradley's report (Eept. U. S. 

 Geol. Surv. of Terr., for 1882, 1873, p. 250) : 



On the west end of the lake, near its northern end, numerous hot springs occur over 

 a considerable area, a few being seen far up on the western ridge. Those near the 

 lake were examined by Mr. [W. R.] Taggart, who reports as iollows: 



The hot springs found on the west bank of Lewis Lake occur mostly in two groups, 

 separated by a low ridge. In the first group ezamiued, all the springs issued from the 

 sides of a marsh, and were mostly covered either with masses of leafy vegetation or with 

 the soft, thick, pulpy masses of fungoid growth so common about the hot springs of 

 the Fire Hole Basins. Some of the springs were constantly bubbling with an escap- 

 ing gas, whose character was not ascertained. The temperatures of all the springs 

 are low. A few of them are as follows: 112°, 122°, 124°, 126°, 126°, l?0o, 138°, 140°, 

 148°. As an interesting fact, I noted that all the springs whose temperatures reached, 

 or exceeded 120° had the growth of fungoid pulp or a deposit of gray geyserite, while 

 those cooler than 120° were covered with leafy vegetation. This cluster of springs is 

 evidently the last remnant of a much more active group, since all along the shore of 

 the lake at this point there are large deposits of old geyserite. At some j)oints this 

 extends far out into the lake. 



The second group of springs differs from the one just described, in that its vents are 

 larger and the water hotter. The springs are surrounded by solid ground, and in 

 their general features resemble the hot springs of the Fire Hole Basins, so that they 

 need no general description. The following are the temperatures and sizes of a few 

 of the principal ones: 1, 152°. 2 feet in diameter; 2, 156°, 10 by 6 feet; 3, 176, elliptical 

 about 40 by 20 feet. 



SPRINGS ON SNAKE RIVER. • 



Under this head I will include the springs on Snake Eiver and its 

 tributaries, not already given in the basins located on drainage of the 

 Snake. 



Springs at junction of SnaJce and Lewis or Lake Fork. — On the east 

 side of Snake Eiver opposite the mouth of Lake Fork is a small group 

 of unimportant springs, in which Mr. Mushback took the following tem- 



* Annual Report of the Superintendent of the Yellowstone National Park, 1880, 

 page 25. 



