230 GEOLOGICAL SURVEY OF THE TERRITORIES. 



columnar porphyry, which disintegrates rapidly, forming pretty solid 

 but very porous slopes, and so yield numerous springs and form many 

 small bogs along the river's edge. Ripe red rasi)berries were abundant 

 along these slopes, but were not seen elsewhere, I believe, on the whole 

 trip. The springy character of these debris is apparently the only serious 

 obstacle to the building of a railroad through the cafion, which has been 

 suggested by parties who desire to facilitate access to the geyser-basins; 

 but the disintegrated rock reconsolidates so well that I should antici- 

 pate no trouble from the springs. A noticeable feature of the river 

 along here is its apparent freedom from freshets ; the vegetation runs 

 down to the water's edge, and no accumulations of drift-wood were 

 observed. Does the heat which escapes so freely in these upper basins 

 remove the snows so constantly and steadily throughout the winter 

 that no accumulations are left to cause freshets by rapid melting in 

 spring? 



The cliffs along the canon at various points are both- beautiful and 

 grand; but we resisted the temptation to give names to all the different 

 points, which is said to have overcome others who have passed this 

 way; though Mr. Raymond has not yet seen fit to publish the names 

 for which he would claim priority. (See Christian Union, I^ew York, 

 May, 1872, p. 437.) 



We had supposed ourselves the only travelers in this region, when 

 suddenly we encountered a party of oiScers and soldiers from Fort Ellis 

 and other northern posts, under the leadership of General Gibbon, who 

 had been visiting the wonders of the Yellowstone and geyser regions. 

 After a brief exchange of courtesies and inibrmation, both parties were 

 again on the march, and we soon emerged from the caiion and camped 

 at the forks of the river. While the main stream came from the south- 

 ward, yet the real continuation of the valley we had been tollowing was 

 occupied by the stream coming from the eastward with perhaps 40 feet 

 of water. As this stream had been partially explored by General Gib- 

 bon, who gave us some useful information concerning it, we have called 

 it Gibbon's Fork of the Madison. Its valley continues eastward for 

 some eight or ten miles, when the depression terminates, the stream 

 entering it from the north, where its sources evidently lie high up on the 

 divide toward Gardiner's River. Following directions given by General 

 Gibbon, we found, about half a mile above our camp, the first indication 

 of our approach to the geyser region, in a cluster of hot springs, which 

 have formed a terrace a little back from the north bank of the stream, 

 and from CO to 80 feet above its level. The water flows from a dozen or 

 more different openings, of which the principal one is a pit from 2 to 3 

 feet in diameter and 15 feet or more in depth, from which water is 

 ejected with constant ebullition to a height of from 1 foot to 3 feet above 

 the level of the surrounding pool. The pool itself is of an irregular 

 form, something like the outline of a goatskin bottle, with the spring 

 in the mouth of it, about 200 feet long by from 50 to 90 feet wide in its 

 main part, while the narrowest part of the neck is from 10 to 15 feet 

 wide. The temperature, at the point of nearest safe approach to the 

 center of ebullition, was 146°; 100 feet distant, the water escaping from 

 the pool gave 120^; while the farthest i)oint of the pool gave 120°, 

 The exit flow was rapid, along a channel averaging about 3 feet 

 wide by 9 inches deep. This had built up its banks a few inches above 

 the surrounding level, and at two or three points the deposit had even 

 bridged the stream. The second pool in size was quadrangular in form 

 and measured about 50 feet on a side. The center of ebullition could 

 not be approached ; and the water along the edges of the pool gave 



