with a hairy or woolly covering are thus secure against frost action. 

 The plants of the Yellowstone region, as far as observed, are well 

 adapted to their surroundings. 



The forests are formed by one tree predominating, P/«z/5 contorta, 

 var. Murrayana, which grows tall and straight, but never reaches 

 any considerable girth. Interspersed among the pines we find sev- 

 eral other arborescent species, namely, Douglass spruce, Pseiuiotsnga 

 Douglasti, the largest tree in the park; balsam, Abies subalpina, pine, 

 Pinus Engelniannii, red cedar, Juniperns Virginiana, poplar, Popii- 

 lus trenitdoides, and willow, Salix, of several species. These forests 

 are of great importance in conserving the rain which falls. Many 

 of the most important rivers of the western United States rise in 

 this region, the Missouri, the Yellowstone, the Wind, the Big Horn, 

 the Platte, the Green (afterward the Colorado), and the Snake, 

 which flows through Wyoming, Idaho and Washington, emptying 

 into the Columbia, and thus reaches the Pacific. 



Yellowstone Park, notwithstanding its wild grandeur as a moun- 

 tain domain, is yet more interesting on account of the geological 

 wonders which are found within its boundaries, namely the geysers 

 and hot springs. The geysers are actively throwing up in jets at 

 periodic intervals, steam and boiling water ; the hot springs are 

 either quiescent, or are bubbling and boiling without explosive erup- 

 tion. They are found in four distinct areas in the Park; the geysers 

 and the hot springs in the Upper, Lower and Norris Geyser Basin,' 

 hot springs only in the Mammoth Hot Spring Region. This divis- 

 ion also accords with the predominating chemical content of the 

 waters. In the Upper, Lower and Norris Geyser Basins, we have 

 springs and geysers which are actively depositing silicious material 

 (sinter); in the Mammoth Hot Spring Basin, springs which are 

 forming calcareous deposits, called travertine. 



Much inquiry hag been instituted concerning the therapeutic value 

 of the mineral springs of the Park. Many hot spring regions through- 

 out Europe and America are resorted to by thousands in search of 

 health. The hot springs of Virginia are visited by hundreds every 

 year. It is said of the Yellowstone region, that the first explorers 

 to ascend the Gardiner River, in 1871, found numbers ot mvaluls 

 encamped on the banks, where the hot waters from Manmioth Hwt 

 Springs enter the stream ; and it is recorded that they were most 

 emphatic in their favorable impressions in regard to their sanitary 



