Rocky Mountains at the bend of the River.

north-north-east*; which makes an angle of rather more than forty-five degrees with the axis of the great chain, from which they project like spurs. The circumstance of the valleys pervading the chain transversely, though with more or less of ascent, explains the reason of the principal rivers on both the eastern and western slopes having their sources beyond the axis of the range, and flowing through it. From some passages in Dr. Hooker's letters, I infer that the Himalayas have a similar configuration.

As the successive spurs and the valleys between them open out to the voyager who descends the

* I have never had leisure to ascertain the true course of these ranges within six or seven degrees, but from the bearings I have taken several times in passing I suppose that south 20° west, and north 20° east is very near their direction.

river, he observes that the eastern faces of the ridges rise abruptly like a wall, while their western flanks are more shelving. This is not, however, uniformly the case, as in some of the ridges lofty escarpments occur also on their western sides.

The height of the almost precipitous cliff of the first mountain at the bend of the river appeared to the eye, from a distance of seven or eight miles, to be eight or nine hundred feet, though the width of the base of the hill did not exceed a mile. Further back, the summit of the ridge terminated by this mountain was judged to be between two thousand and two thousand eight hundred feet high. The heights here mentioned were estimated solely by the eye, and as in this climate heights and distances are very deceptive they must be considered as very rough approximations. No trees could be detected on the summits when examined with the telescope, but the lower hills, and the slopes to the height of a thousand feet, were well wooded.

The first range re-appears on the east side of the river, and is seen at intervals running in the direction of M'Vicar's Bay of Great Bear Lake, whose basin interposes between its termination and the granite and gneiss that skirt the eastern arms of that lake.

At the bend of the Mackenzie, the valley which

interposes between the first and second ridges does not appear to exceed five miles in width, but it was seen too obliquely to enable us to form a correct judgment. The river flows through this valley for upwards of fifty miles, when, making a small bend to the westward, it escapes across the ridge. Thus far the second ridge* runs on the west bank of the river, showing a bold precipitous craggy side at intervals, some parts being concealed from the voyager by the intervening swelling grounds which form the floor of the valley. Where the river cuts it, a high island of limestone stands in mid channel, and on the east bank, a round-topped hill, named the "Rock by the River's Side" † (Roche qui trempe à l'eau), rises precipitously from the water's edge to the height of five or six hundred feet or more. The base of this hill scarcely exceeds a mile in diameter, and most of the ridges seem to be of similar breadth. From the Rock by the River's Side the ridge continues, but with interruptions, onwards in the same direction to the elevated promontory of Great Bear Lake, named Sas-choh etha (Great Bear Hill), which stands between Keith's and M'Vicar's Bays.

The other spurs, which succeed these down to the delta of the river, rise in like manner like rugged walls from the surrounding low, undulating country,

* Partly seen on the right-hand side of the woodcut, p. 172. † See woodcut, p. 182.

the stream escaping through them by successive gaps. Many of the escarpments, when seen from a distance reflecting the rays of the sun, look as bright and white as chalk cliffs; and but for information which I have gleaned from voyagers who have crossed them, I should have been in doubt whether they were not formed of that material or of white sand, instead of being hard limestone.

At this date only a few patches of snow remained in the hollows having a northern exposure; but in the following year they were entirely covered with snow until late in June, and for some weeks after all the low country had become quite bare. Both the first and second ridges are distinctly stratified at the bend of the river, and seemingly capped with trap. Where they and the succeeding ridges are cut by the river, limestone is the chief rock that is visible; but I have had no opportunity of examining the principal cliffs, and have made but a very cursory inspection of any. The spurs which reach the Mackenzie consist, perhaps, wholly of limestone. Sandstone exists in their vicinity, but I believe it is a newer deposit, belonging to that which forms the floors of the valleys, and rests unconformably on the tilted beds of the ridges. No organic remains were detected in any of the highly inclined beds, but gypsum and chert are of frequent occurrence.

Traders who have crossed from the Atlantic to the Pacific slopes of the continent say that there

are fourteen or fifteen ranges of hills, and that when they are viewed from the summit of a peak, the mountain tops appear to be crowded together in great confusion, like a sea of conical billows. My informants could not tell me whether granite, clay-slate, or trap rocks entered into their composition or not; but it is probable that such is the case, as we know it to be in more southern latitudes. received specimens of semi-opal, plumbago, and specular iron, gathered on one of the ridges. The more westerly ranges have obtained from the traders the name of the Peak Mountains.

I

On the Mackenzie, a shaly formation makes the chief part of the banks, and also much of the undulating valleys between the elevated spurs. It is based on horizontal beds of limestone, and in some places of sandstone, which abut against the inclined strata of the lofty wall-like ridges, or rest partially on their edges. Covering the shaly beds, there exists in many places a deposit of sand, sometimes cohering so as to form a friable sandstone; and where a good section of the bank occurs, a capping of gravel and boulders, of various thickness, is seen crowning the whole. The shale crumbles readily, and often takes fire spontaneously, occasioning the ruin of the bank, so that it is only by the encroachments of the river carrying away the debris that the true structure is revealed. The boulders