S4 DAVKNHUKT ACADKMY OF NATUKAJ. SCIENCES, 



Avhat in other respects would often be charming- and ])icturesque. 

 From this plain, formed wholly of lava, covered with a thin coat of 

 sand, and still scantier stratum of vegetable soil, which, however, 

 is generally absent, and nothing grows upon this sterile surface but 

 cactus and artemisia. 



The lava plain of Idaho is seamed in a few places by some unim- 

 portant streams, the major part of them emptying into Snake River, 

 or its main affluent, Henry's Fork. Aside from this, universal 

 drouth prevails, and ''Viooths <^*f Idaho is doomed to eternal ster- 

 ility. Universally, all the rivers and smaller creeks flow in 

 deep crevices in black honey-combed lava, abounding in rapids 

 and deep pools of cool, clear water, and in magnificent trout. 

 Snake River, the main southern branch of the majestic Columbia, 

 has cut out its bed in tliis dark lava. It is a fine deep river, swift, 

 impetuous and dangerous. The x\merican Falls, some 70 miles 

 below Fort Hall, are stupendous and magnificent. Here the whole 

 water of this magnificent stream is precipitated down a stej) in the 

 lava field over 140 feet high. 



In the course of our exploration, when surveying our return line 

 h\ the valley of Madison Fork and Fire Hole River, we left the 

 last named stream on our left, and to avoid its steep and tangled 

 canons, we prolonged our line of survey over the main Rocky 

 Mountain range by Raynolds' Pass to Henry's Lake, the source of 

 Henry's Fork of Snake River. From this lake we turned sharply, 

 eastward crossed the Rocky Mountain by the Tahgee Pass, 7470 

 feet above the sea, and reached Fire Hole Valley and the marvel- 

 ous geysers of the National Park by an easy natural wagon road. 

 Fire Hole River, from the west edge of the National Park to the 

 several geyser basins, flows through a valley cut through lofty, 

 picturesque, but ragged Trachyte Mountains, covered with scrub 

 pines, with glades interspersed, clothed with scanty grass. The 

 first canon in the National Park is grand and weird, seamed with 

 traces of recent volcanic action. Its wildness was rendered more 

 salient from our continued watch night and day to prevent sur- 

 prise from small bands of hostile Indians driven eastward by Gen. 

 Howard's campaign against hostile Piutes and Bannocks. With 

 some labor, and by vigorous exertion, we carried our line of recon- 

 noisance up to the Upper Geyser Basin, our wagons being the sec- 

 ond only that have penetrated to that point. 



I confess that my ideas are barren and my mind bewildered by 



