GEOLOGICAL SUEVEY OF THE TEEEITOEIES. 43 



limit of arborescent vegetation. This also forms one of the radiating ridges, 

 which extends down from the axis of the range to the plains, and sepa- 

 rates the valleys of Smith's and Black's Forks. Sometimes it is several 

 miles in width, but toward the crest of the range the ridge of separation 

 is not more than two hundred yards wide. Standing on either side of this 

 ridge, the view that meets the eye toward the sources of these streams 

 can hardly be surpassed for ruggedness and picturesque beauty. The 

 valley of Smith's Fork seems to be altogether one of erosion, cutting 

 through the uplifted strata nearly at right angles. The beds are well 

 shown in the sides of the valley for miles, inclining at angles from 20° 

 to 35°. At the very sources of both Smith's and Black's Forks are 

 pyramidal or conical peaks most distinctly stratified, and apparently 

 horizontal, or nearly so, with the summits above the limits of perpetual 

 snow, and from fifteen hundred to two thousand feet above the springs 

 that give origin to the streams below. These peaks or cones are vast 

 piles of purplish compact quartzite, resembling much Egyptian pyra- 

 mids on a gigantic scale, without a trace of soil, vegetation, or water. 

 One of these remarkable structures stands out isolated from the rest, in 

 the middle of the valley of Smith's Fork, which we estimated to rise 

 fifteen hundred feet above its base; and so much like a Gothic church 

 did it appear, that the members of my party gave it the name of Hay- 

 den's Cathedral. 



From Carter's Plateau I descended into the valley of Smith's Fork, 

 and after traveling about three miles over ridge after ridge of sand- 

 stone and quartzite, inclining at various angles from 20° to 30°, I came 

 within a short distance of the base of this cathedral, when I found that 

 it formed the south side of an anticlinal, and that the trend of the 

 valley was northeast and southwest. It would seem that while all the 

 beds on the north side of the anticlinal dip at a large angle, those on the 

 south side were forced up in a nearly horizontal position, inclining 

 southwest only 3° to 5°. The valley is full of little lakes, which form 

 an interesting feature of the scenery of the Uintas. In most cases they 

 are the result of land-slides, and occur at different elevations, depend- 

 ing upon the conditions that bring them into existence. Carter's Lake 

 is a beautiful sheet of water, inclosed on one side by a semicircular wall 

 of purplish sandstone and slates, and on the other by a dense growth of 

 spruce trees. The depression for the accumulation of the waters of this 

 lake was formed by an immense mass of rock sliding down from the 

 ridges above. The side of the mass opposite the ridge from which it 

 was detached would be the highest, forming a rim for the depression. 

 Springs of water ooze out of the sides of the ridge, snows melt, and 

 the waters flow down and gather here, and soon a little lake is formed. 

 This one is three hundred and fifty yards in length, and eighty yards in 

 width. 



' It is quite plain that these slides have been the chief agency in 

 enlarging these valleys, for even at this time we see the evidences of it 

 everywhere, both at the head of Smith's and Black's Fork. The valley 

 extends from half a mile to a mile above the anticlinal valley, and in 

 the dry season of autumn, far above the existence of water. I am inclined 

 to believe that the origin of the stream and its valley began in this 

 anticlinal opening, and that the valley has extended up above it by the 

 sliding down of vast masses of rock which were swept downward by the 

 waters. On the west side of the valley of Smith's Fork, near its head, is 

 a vast semicircular notch or indentation, nearly half a mile deep, which 

 has been wholly formed by these slides. In the valley below, which is 

 five hundred to eight hundred feet deep, are half a ( bzen lakes, occupy- 



