PEAtE.] MAMMOTH HOT SPEINGS OF GAEDINER's RIVER. 83 



F. to 143° F., and in 1872 they were 130° F. to 148o F., indicating that 

 there has been little if any change in this respect. 



2s5"o. 48. — Above the mounds on a fiat area there are several old spring 

 holes, only one of which contains water at the present time. The others 

 have probably been extinct for a long time. The water in the conical 

 mound, which is at present the only spring here, has a temperature of 

 only 83° F. Above this flat we find several small springs. 



Ko. 48 a. — This is at the foot of a cave-like opening in the deposit, 

 and is a mossy-lined bole with several points of ebullition or bubbling. 

 The temperature is 90° F. Above it are several holes, the sites of old 

 springs. 



No. 48 b marks the location of several small and unimportant springs 

 that are almost concealed by the grass at the foot of the ridge that ends 

 the rough part of the thirteenth terrace. The temperatures are 63° F. 

 and 91° F. There are at present no active springs above the fourteenth 

 terrace. 



At a number of places in the old sediments caves are found, the 

 roofs of which are ornamented with stalactites, and in which bones of 

 animals are found. One is described by Professor Comstock in his re- 

 port,* which he considers to be the basin of an extinct spring. The 

 opening was hopper-shaped, 6 feet long by 3 feet in width, and beneath 

 was a chamber 9 feet in height, with a steep, sloping floor covered with 

 a thick deposit of vegetable mold. On one side of the sloping floor, 

 near the bottom, the skull and bones of a bison. These caves are the 

 resort of wild animals, and the bison bones were either carried in by 

 them, or, as Professor Comstock thinks, the animal fell through some 

 larger opening and passed into the chamber or cave trying to find a pas- 

 sage out. The bones were imbedded in the soil, from which he draws 

 the conclusion that the animal perished a long time ago, but at a much 

 later period than the date of the extinction of the spring. 1 have al- 

 ready referred to the old compact deposit found on the long mountain 

 ridge south of the springs. This was visited by Dr. Haydeu in 1871, 

 who thus describes it (Report for 1871, page 71) : 



Upon the margins of the mountain, high above the present position of the hot 

 springs, is a bed of very white or yellowish- white limestone, 50 to 150 feet thick, and 

 appearing in the distance like very pure Carboniferous limestone. It is regularly 

 stratified, aud the jointing is complete, and immense masses have fallen down'on the 

 slope of the mountain side. There is a belt a mile long and one-fourth of a mile wide, 

 covered with immense cubical blocks of the limestone 50 to 100 feet in each dimen- 

 sion, usually with the wedge-shaped end projecting upward, as if the mass had slowly 

 fallen down as the underlying rocks were worn away .by erosion. So thickly is this 

 belt covered with these huge masses that it is with the greatest difficulty one can 

 walk across it. It would seem that this bed must at one time have extended over a 

 portion or all of the valley of Gardiner's River, Much of the rock is very compact 

 and would make beautiful building-stone, on account of its close texture and color, 

 and it could be converted into the whitest of lime. If the rocks are examined, how- 

 ever, over a considerable area, they would be found to possess all the varieties of 

 structure of a hot-spring deposit. Some portions are quite spongy, and decompose 

 readily ; othems are made up of very thin laminae, regular or wavy, enough to show 

 the origin of the deposit without a doubt. But in what manner was it formed? I 

 believe that the limestone was precipitated in the bottom of a lake, which was filled 

 with hot spri'^gs, much as the calcareous matter is laid down in the bottom of the 

 ocean at the present time. Indeed, portions of the rock do not differ materially from 

 the recent limestones now forming in the vicinity of the West India Islands. The 

 deposit was evidently laid down on a nearly level surface with a moderately uniform 

 thickness, and the strata are horizontal. 



The Gardiner's River Springs have frequently been compared to the 

 Te Tarata Springs of New Zealand, where the basins have the same 



* Reconnaissance of Northwest Wyoming, pp. 212, 213. 



