PEALE.] LOWER GEYSER BASIN OF FIRE HOLE RIVER. 135 



CHAPTER VII. 



LOWER GEYSEE BASIN OF FIRE HOLE RIVER. 



The Lower Geyser Basin is a wide valley tbat extends southward 

 from the junction of the East Fork of Fire Holfe Eiver with the main 

 stream. Several smaller branches come in from the west, above the 

 mouth of the East Fork, and one on the east. The entire area is be- 

 tween 30 and 40 square miles, and over this the springs are scattered 

 in groups. In this chapter we have catalogued 693 springs, including 

 the Egeria springs, all of them being shown on the map. There are 1 7 

 known geysers in this Basin. The central portion of the valley ex- 

 tending from Twin Buttes to East Fork Butte is a wide flat plain of 

 some 6 or 7 square miles, partially timbered, but for the most part 

 bare and covered with spring deposits or marsh. The view of this 

 plain on a frosty morning is interesting, as columns of steam are 

 seen rising from all parts of it. To Lord Dunraven it gave the im- 

 pression "that some modern cities of the Plain had been overwhelmed, 

 and had so lately sunk amid flames into the bowels of the earth that 

 the smoke of their ruins was still ascending through white heaps of 

 smoldering ashes."* The general elevation of the basin is 7,236 feet, 

 and above this the surrounding plateau rises from 400 to 800 feet, the 

 slopes being heavily timbered. 



Geology. — As to the geology of the Lower Basin the reader is referred 

 to the report of Mr. Holmes for the details. The rocks of the plateau 

 are rhyolites, and in the remnants of lake-beds, which are formed in the 

 buttes scattered through the valley, we have the evidence of the former 

 existence of a lake. Professor Bradley was inclined to think that the 

 two Geyser Basins are remnants of a huge crater, as he found dips 

 towards the Basin in the rocks on several sides.t I am, however, 

 inclined to think that these inward dips are due to a depression in the 

 basins caused by a deep-seated fissure, through which the thermal waters 

 are forced to the surface. The general slope of the plateau, interrupted 

 only by this depression, continues to the south or southwest, indicating 

 a flow towards the south or southwest. 



Professor Corastock thinks that the Geyser Basins not far in the past 

 were overflowed by siliceous waters, because — 



lu some portions of these districts the trees are luailied for 9 feet above the base of 

 the trunk with a white incrustation, giviuj; them something of the appearance of the 

 whitewashed trees in an orchard. t 



I think this condition can be more readily explained as follows: The 

 hot water flowing from the springs surrounds the bases of the trees and 

 kills them. Upon evaporating, the sediment deposits about the trees 

 and the water standing upon this is carried w\) the trunk by capillary 

 attraction, and evaporating from the outside of the trees leaves the white 

 siliceous deposits referred to above as the result of inundations, having 

 a depth of 2 feet. 



History. — In the early accounts of this region this locality was spoken 

 of as the Burnt Hole, and as such was vaguely indicated on the mai)s 

 from hearsay. Thus, on the map accompanying Eaynold's report of his 

 expedition of 1859-'60, the region east of Henry's Lake, across the mount- 



*The Groat Divide, p. 257. 



t Report U. S. Geol. Survey, 1872, p. 241. 



t Reconnaissance of Northwestern Wyoming, 1873, p. 258. 



