GEOLOGICAL SURVEY OF THE TEREITORIES. 239 



site sides, which must be alternately wetted by the steam and 

 spray and dried by the wind, have the beautiful pearly luster, 

 partly due to the thin lamination of its structure and partly to the 

 opaline composition of the material. The west end of the pool is shal- 

 low, and the water flows from it to the foot of the slope over broad and 

 shallow terraced steps, resembling the deposits of the calcareous springs 

 of Gardiner's Eiver, though on a much smaller scale. The main pool 

 nowhere showed a higher temperature than 187°, but a little vent two 

 feet from its rim gave 19^°. Several small pools and vents were noticed 

 in the adjoining timber, but none that deserve special mention. 



Though this whole valley is more or less miry, yet its luxuriant 

 growth of grasses and other forage-plants attracts the game, whose trails 

 abound in every direction ; and this is probably the biest location for a 

 ranch that can be found in the Lower Basin. The cam ping- ground on 

 the east side of the valley is low and damp, so as to be unhealthy for a 

 prolonged stay. If a hotel were to be located in the region, the best 

 place would probably be on the foot-hills on the east side of the river, 

 between the Lower and Upper Basins, since cold springs and abundant 

 forage within easy reach would there be combined with dry locations for 

 building, while the wonders and beauties of either basin would be but a 

 short distance off. 



Most of the cold ponds found at intervals throughout the valley are 

 plainly extinct hot springs ; but, among the timbered hills about a half 

 mile southwest of the White Dome Geyser, there is a large one which 

 is not of this character. It has no outlet. Just south of it is another 

 hollow, once occupied by a still larger pond, of which only a small pool 

 now remains, while the old bottom is covered with a very luxuriant 

 growth of grasses and sedges. 



Between the two basins. Rabbit Branch enters the river from the 

 east, with a strong flow of hot water. The whole of its short valley is 

 filled with warm and hot springs. The principal one, at the head of the 

 northern fork, a large steaming pool, reaches 148°, and is not surpassed 

 by any of its neighbors. About the forks of the stream, a considerable 

 cluster of steam-vents, idooIs, and mud-pots give various temperatures 

 np to 186° and 192° ; yet, as a whole, the group shows but little activity. 

 Steam-vents and small pools run far up the side of the mountain. At 

 the head of the southern fork, separated from the last group by from 200 

 to 300 yards of timber, is a cluster of mostly small springs, which shows 

 rather greater activity. The principal vent is situated under the pre- 

 cipitous bank, and is apparently working backward by undermining the 

 overhanging rock. Large masses have already slipped off and fallen into 

 the narrow pool, so as to greatly interfere with the free motion of the 

 water; and, accordingly, though steaming and boiling furiously, it 

 spatters only a short distance. It was iuipossible to reach the boiling 

 center ; the nearest accessible part of the pool gave a temperature of 

 192^. Crossing the spur to the southward, we found, instead of a broad, 

 flat valley, like the one we had just left, a narrow, steep ravine, partly 

 with precipitous sides, at only one point of which did we see slight indi- 

 cations of warm springs. There was, however, an abundant flow of cold 

 springs, fully equal in volume to that of the hot springs of Rabbit 

 Branch. As no difference was noticed in the rocks of the two hollows, 

 we could refer their difierence in form of erosion only to the solvent 

 power of the hot waters. 



As we approach the Upper Basin, we find considerable stretches of 

 swaraijy flats, now nearly destitute of any signs of hot-spring action, 

 but probably occupied by such sxjrings in former times. In the Upper 



