268 GEOLOGICAL SUEVEY OF THE TERRITORIES. 



eiiMy draining a considerable area of -the mountain. It approaches the 

 river by a succession of cascades over successive layers of the sand- 

 stones. As we descend the river, these beds come up in two antic! in als, 

 one low and flat and the second mountainous, with dips reaching 70°, 

 and coming down steeply to the river on both sides. The axis of the 

 second anticlinal is occupied by a narrow fold of limestone, through 

 which escape several warm springs. A small cluster of these, escaping 

 among the gravel in the edge of the river, on the south side, emit an 

 abundance of sulphureted hydrogen. Though somewhat mixed with 

 the river-water, they gave a temperature of 117°. About a hundred 

 yards below this, a group of calcareous springs has built up a dam of 

 tuff, so as to flood several acres about the vents, which are now inacces- 

 sible. The general flow from the pool gave a temperature of 94°. Just 

 opposite these springs, in the lower part of the sandstones, as they 

 re-appear on the west side of the anticlinal, there are exposures of two 

 or three heavy beds of black, calcareous shale and friable clay, with 

 some harder bituminous mud-stones, which appear, from short distances, 

 precisely like coal outcrops. Fragments of teeth and bones, probably 

 belonging to amphibians, occur in these layers. Above them there are 

 some thick beds of chert. 



Here the river turns south again, and runs for about two miles along 

 the west side of the anticlinal, with sharp slopes on either banks. Turn- 

 »ing west again, we cross three auticlinals, in the third of which" consid- 

 erable displacement has taken place, so that the Carboniferous comes 

 boldly up, and, after this, forms the mass of the mountain clear through 

 the caiiou. The lower portion of these beds consists largely of sand- 

 stones and shales, though including heavy beds of limestone ; higher 

 up, the limestones form a heavy mass for several hundred feet, partly 

 compact, partly fragmentary, overlaid finally by more shaly beds, 

 making a total thickness of 2,000 feet or more. A few fossils of the 

 genera Spi-nfer, Macrocheilus, and Zaphrentis were seen in the debris. 

 The lower layers weather to nearly white, while the upper ones are 

 strongly buff. All through this series, the caiiou is narrow, with steep, 

 often perpendicular, slopes and hardly any bottoms. The river mainly 

 occupies a deep channel, with a broad shelf of rock on one or both 

 sides, which is barely covered at this season. Crossing would be impos- 

 sible without swimming the stock. Many of the steep slopes are covered 

 with spruces, and their angular tops, lapping over each other, on the 

 opposite side of the canon, give the effect of diamond-slating on a roof, 

 though with the angles reversed. Upon these limestones we begin to 

 find again great numbers of the small maples seen farther s-outh. These 

 are said by the hunters to be somewhat on the increase in this region. 



About ten miles through these limestones bring us to the mouth of 

 the caiion. Through much of its upper course the stream is quite rapid, 

 and almost deserves the name. Mad River, applied to this part of it by 

 the early trappers ; but there is little that would have proved trouble- 

 some *to experienced voTjageurs, and probably none that would prove 

 really dangerous. (See Irving's Astoria, chapter xxxi.) 



The terraces, though only fragmentary through the canon, now spread 

 out into broad sage-covered flats on either side of the river, and the 

 higher slopes become much more rounded. Just at the mouth of the 

 caiion, John Gray's E-iver, which heads far to the south, on the divide 

 toward Bear Eiver, comes from the southeast, tlirough the same mountain- 

 mass, and with apparently just such a canon as the one we have just 

 left. At its mouth, a heavy mass of cemented bedded gravel shows 



