IOWA ACADEMY OP SCIENCES. 
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pretty mountain stream, which has its sources in the great 
range just north of this valley, and joins the Bear a mile eastt 
of the Springs. Some four miles up, this creek has made for 
itself a wild, deep gorge or canon, and here, in 200 or 300 
yards, it falls perhaps 200 feet. In this canon great masses of 
rock lie in every position and these show plainly a bedding, 
although the main walls of this canon are almost vertical 
sheets of metamorphic rocks. 
At a point some six or seven miles northwest of Steamboat 
Springs, at some springs we visited, the temperature of the 
water is said to be about 160 degrees F. The rocks are, in 
part, at least, very dark colored, compact and fine grained, 
resembling diorite. Enough has been said to show that the 
Park range, immediately north of Steamboat Springs, is 
largely metamorphic, abounding in granites, syenites and vol- 
canic rocks. In this vicinity the valley of the Bear is from 
one-half mile to a mile in width. Directly opposite the 
village, which is almost wholly on one street on the north side 
of the river, is a rather lofty and rugged mountain, but for the 
most part the country on the south side of the Bear is much 
less precipitous and is not covered by timber like the moun- 
tains close on the north. The valley here has undoubtedly 
been the seat of an immense glacier, which was well supported 
from the north by great numbers of glaciers lying on the 
southern face of Park range. 
One very conspicuous moraine lies in the village, and to 
improve the single straight street this moraine has been cut 
transversely. In the village there are four charming little 
creeks, all coming from the mountains on the north. Not a 
single creek enters the Bear river, for several miles, from the 
south. Opposite the eastern or upper end of the village, 
some 300 feet above the valley of the river, is an “onyx 
mine.” Here a horizontal tunnel has been carried perhaps 
200 feet into the side of the mountain. A cross section of this 
tunnel is not less than six feet square. It is perfectly dry and 
is wholly in what seems to be unmodified drift. The onyx is 
scattered through this drift in pieces varying from a cubic 
inch to blocks three or four feet square and eight or ten feet 
long. These pieces show, in many cases, unmistakable evi- 
dence of erosion or weathering, and they are so packed in with 
the clay and granite pebbles that we could hardly pull out 
small pieces from the walls of the tunnel. How extensive the 
