GEOLOGICAL SURVEY OF THE TEERITORIES. 231 



only 113^. The smaller flows varied from 110° np to 134'^, and in one 

 case up to 150°, Several old openings along the outer edge of the 

 terrace were long since deserted ; and the flow is now only from higher 

 levels farther back. The deposit thus appears to stop up the channels 

 and so to force the water back until it finds or makes new openings in 

 the disintegrating jointed masses of the porphyry which form the 

 underlying stratum and the hill behind the terrace. At only one point 

 is there a strong flow from below: this is on the immediate bank of the 

 stream, and the temperature, being only 92°, indicates a mingling of 

 cold and hot springs. 



The other fork of the Madison has from this point been called the 

 Fire-Hole Eiver ; but it is hardly a distinct stream, and should more 

 properly be called the Fire-Hole Fork of the Madison. For about five 

 miles above its mouth it passes through a succession of small caiions with 

 precipitous walls, which render the stream inaccessible in most places. 

 At one point there is a fine fall of about 30 feet. There are also two 

 long successions of rapids, with many points of artistic beauty. After 

 emerging from the caiion, and getting far enough out in the bottoms to 

 clear the timber and look back, we found that we had risen so rapidly 

 as to be now on the level of the top of the cliffs on the south side of 

 the great caiion through which we had passed on the previous day, 

 while those on the north side are seen to rise rapidly from the borders 

 of the caiion into a lofty mountain-mass, whose northern slopes must 

 give rise to some of the head- waters of Gallatin Eiver. 



We now come to the stream which Dr. Hayden descended in coming 

 from the Yellowstone in 1871, and which was named to him, by his 

 guides, as the east fork of the Madison. That name has been applied 

 to at least three different streams- If such a point-of-compass title is 

 ever i)roper, this should most properly belong to that part of the stream 

 which comes out of the Gallatin Mountains and joins the Madison nearly 

 opposite Tyghee Pass. We now propose to call the stream which joins 

 the Madison- at the lower end of the geyser-basins Hayden's Fork, after 

 its first known explorer. Here we first met with the hot springs of 

 the lower geyser-basin. One of the first, directly on the bank of the 

 river, had a temperature of 197°. In the mucilaginous deposit upon its 

 sides. Dr. Curtis found skeletons of diatoms, but no living ones; but, 

 fur further statements of these microscopical observations, I must refer 

 to his detailed report. About a quarter mile farther up the stream, 

 al>ove the first bend, a strong spring, boiling intermittently, but rarely 

 over a foot in height, with a pool about 25 feet long by from 6 to 12 

 feet in width, gave a temperature of 200°, the highest found in the 

 whole region, and a fraction above the boiling-point theoretically due 

 to that elevation. And now we were in the midst of hot springs and 

 geysers, and shortly camped on a wooded knoll which overlooks a con- 

 siderable X)art of the Lower Basin. We had expected to meet Dr. Hay- 

 den's party in this neighborhood, and soon learned that they had reached 

 the Basin, coming from Bozeman, via the Yellowstone valley, a few hours 

 before us, and had pitched camp about a mile farther east. Next morn- 

 ing, therefore, we moved over and joined them. The collections of both 

 parties were now packed u[); specimens were gathered from the 

 geysers ; and Mr. Stevenson started with them, on August 17, for Vir- 

 ginia City, both to ship the specimens and to procure provisions for our 

 return trip. Dr. Hayden's party also started down the Madison, on the 

 20th, and we were again nearly alone, th'ough a few visitors from Mon- 

 tana were also in the Basin and camped near us part of the time. 

 Among them was probably the first lady who ever saw the geysers — 

 Mrs. Stone, of Bozeman. * 



