112 



EEPOET UNITED STATES GEOLOGICAL SURVEY. 



also, and what most distinguishes these springs is the presence of calca- 

 reous matter in the deposits, which is the result of the water passing 

 through limestone. The sulphur vents, however, are located on tra- 

 chyte, on which are probably remnants of lake deposits. In this re- 

 gion it is somewhat difficult to tell at times what is the direction of the 

 drainage, as the timber is heavy and a number of depressions exist 

 which appear to have no outlet. 



Eecapitulation of Hay den's Valley Springs. 



Ifame of groups. 



Forest G-ronp 



Crater Hills Springs 



Mud Volcano Springs 



Violet Creek Springs 



Prairie Group (or Warm Spring Creek Springs) 



Boiling Springs, near source of Warm Spring Creek . 

 Brimstone Group 



Total springs . 



J5.S 



20+ 

 56-1- 

 80 + 

 22+ 



128+ 



°F. 

 390 

 197 

 391 

 194 



194 



The only genuine geyser described in this chapter is the " Mud Geyser" 

 of Mud Volcanoes, unless the Caldron near it should turn out to be one. 

 The geysers described by Comstock in the Boiling Springs are probably 

 small, and might be classed as pseudo-geysers, although one of them, he 

 says, throws the water to a height of 8 feet. 



CHAPTER IV. 



SPRINGS OP YELLOWSTONE LAKE. 



Yellowstone Lake is the largest body of water within the Park, and its 

 shape has often been compared to that of an outstretched hand, of which 

 the thumb and index and little fingers are swollen and deformed, and the 

 other two fingers dwarfed. Of the arms representing the latter, one in 

 dry seasons becomes a separate lake, which has been named Delusion 

 Lake. The greatest length of Yellowstone Lake from north to south is 

 20 miles, and the width from the eastern shore to the west side of the 

 west arm a little over 14 miles. The main body measures about 7 by 12 

 miles. Its greatest depth is 300 feet. 



On early maps of this region a lake is indicated as the head of the 

 Yellowstone Eiver, in about the position of Yellowstone Lake, but with 

 the shape anything but correctly shown. On some of these maps it is 

 called Eustis's Lake and on others Sublette's Lake.* On later maps it 

 appears as Yellowstone Lake, and is so named on the the map accom- 

 panying the report of Captain Eaynolds's expedition of 1859-'60. 



*An examination of the maps illustrating vol. xi of the reports of surveys for the 

 Pacific Railroad shows that on the maps as known in W95 the Yellowstone Eiver is 

 not even indicated. A sketch made in 1818 has Eustis's Lake, but the shape is incor- 

 rect. This map was published by General Land Office. On Fiuly's map of 1826, no 

 lake is shown, nor is it indicated on Bonneville's map of 1837. 



