118 EEPOET UNITED STATES GEOLOGICAL SUEVEY. 



SPEINGS ON WEST OE SOUTHWEST AEM OF YELLOWSTONE LAKE, AT 



HOT SPEINGS CAMP. 



This group of springs was first visited by the Doane- Washburn party, 

 in 1870. It has not been visited by the writer since 1871, but a portion 

 of the notes then taken were not used in the preparation of the report 

 for that year, which was only a preliminary report.* The locahty is 

 known as Hot Springs Camp, and has become a favorite resting place 

 for those who go to Yellowstone Lake from the Upper Geyser Basin. 

 To one who has just seen the powerful geysers of the latter region the 

 springs of this group will not seem to present much of interest, yet these 

 springs are not uninteresting. They are divided into mud springs or 

 mud puffs, pulsating springs, and quiet springs. They are scattered 

 along the shore of the lake for about two or three miles. The upper ones 

 maj^ be considered as a subgroup, although the interval between has 

 numerous springs scattered along the shore of the lake. 



The lake shore is composed of thick siliceous deposits which have been 

 worn into a blufl' of 20 to 25 feet in height. Most of the springs are 

 situated on this terrace, although a number are at the water level and 

 extend out into the lake, where they have formed, in two instances, 

 cones which are surrouoded by the water of the lake. The deposit 

 extends out beneath the waters of the lake, and numerous points of 

 bubbling attest the presence of spring orifices at various points in the 

 lake. The deposit forming the shore or bank is laminated, and on it is 

 a considerable thickness of broken up geyserite, which in some places 

 has been cemented into large masses. 



Lower Group. — The springs that first attract attention are the cones 

 in the lake. One of these we named the "Fish Pot," from the fact that 

 persons standing on this cone may catch trout in the lake and, without 

 moving from their position, cook them in the spring without taking them 

 from the hook. 



The cone has been built up by laminae of the siliceous deposit until it 

 has a height of three feet above the level of the lake. Its shape is that 

 of a truncated cone, and the water in the spring on top has a temperature 

 of 160° F.f A spring on the shore north of this gives a temperature of 

 143° F. These springs affect the temperature of the surface of the lake, 

 as we found on bathing in it. A layer of hot water is on top of the cold. 



South of the Fish Pot, along the lake shore, is a line of springs with the 

 following temperatures: 191°, 130°, 153°, 154°, 153°, 153°, 141°, 191° F. 

 These are large springs with deep basins, in hard deposits. Some have 

 an overflow, while others were quiet, although they may, and doubtless 

 have, periods of increased action. The water is beautifully colored, of 

 an azure tint, as in the springs of the other regions. One of the boiling 

 or throbbing springs is divided by a bar or bridge of deposit into two 

 basins. 



A few hundred yards back from the lake shore there are the — 



Mud Puffs. — The mud puffs are situated in a bank of clay (to which 

 their peculiar character is due) of bright pink and red colors. The basin 

 is about 50 feet in diameter, and the center i& a seething mass of very 

 finely divided mud, which on drying is lighter in color, and becomes a 

 hard mass resembling chalk. Around the edges of the basin are small 

 conical mounds of mud, about a dozen in number, of 2 or 3 feet height, 

 from which the mud is spurted at irregular intervals to a height of 3 or 

 4 feet with a thud-like noise. 



*See introduction, Eeport of U. S. GeoL Surv. of Terr., 1871, p. 165. 



t All the temperatures given of this group were taken in 1871, unless otherwise stated. 



