of the Yellowstone and Firehole Rivers. 173 
In the Lower Geyser Basin on both sides of the Firehole, 
even Aad among the foot hills of the mountains on either side, 
of the most interesting phonies that can well be ima 
columns of steam are rising from a cidaaana vents, pester 
shrouding the valley as with a dense fo of the cit 
dense black smoke arises in hundreds of Soin flavin of 
the white feathery clouds of steam. 
pper Geyser Basin is located very near the source of 
Firehole river, and between it and the Lower Geyser Basin 
there is an interval of about five miles in which the hills come 
close to the river on both sides, and the springs occur only in 
small groups. Although possessing some interest, yet there 
i t t 
Stream SPRING AND CONE. 
which we call Iron Spring Creek, on which are located many 
more prings, as the chart indicates. * This stream receives its 
name from the vivid yellow and pink clays, on both sides, from 
mouth to source. Ascendin ng the Firehole, we find the sur- 
face, on both sides of the river, covered with a thick siliceous 
