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Sierra Club Bulletin 



the valley, and expending the down-thrusting power with which 

 they were endowed by virtue of the declivity of their channels, 

 the trunk flowed up out of the valley without yielding much 

 compliance to the crooked and comparatively small river canon 

 extending in a general westerly direction from the foot of the 

 main valley. In effecting its exit a considerable ascent was 

 made, traces of which are to be seen in the upward slope of the 

 worn, rounded extremities of the valley walls. Down this 

 glacier-constructed grade descend both the Coulterville and 

 Mariposa trails ; and we might further observe in this connec- 

 tion that, because the ice-sheet near the period of transition 

 to distinct glaciers flowed southwesterly, the south lips of all 

 Yosemites trending east and west, other conditions being equal, 

 are more heavily eroded, making the construction of trails on 

 that side easier. The first trail, therefore, that was made into 

 Yosemite, was of course made down over the south lip. The 

 only trail entering the Tuolumne Yosemite descends the south 

 lip, and so also does the only trail leading into the Kings River 

 Yosemite. A large majority of deer and bear and Indian trails 

 likewise descend the south lips of Yosemites. So extensively are 

 the movements of men and animals controlled by the previous 

 movements of certain snow-crystals combined as glaciers. 



The direction pursued by the Yosemite trunk, after escaping 

 from the valley, is unmistakably indicated by its immense lat- 

 eral moraines extending from its lips in a west-southwesterly 

 direction. The right moraine was disturbed by the large tribu- 

 tary of Cascade Creek, and is extremely complicated in struc- 

 ture. The left is simple until it comes under the influence of 

 tributaries from the southeast, and both are further obscured by 

 forests which flourish upon their mixed soil, and by the washing 

 of rains and melting snows, and the weathering of their boul- 

 ders, making a smooth, sandy, unmorainelike surface. It is, 

 therefore, the less to be wondered at that the nature of these 

 moraines, which represent so important a part of the chips hewn 

 from the valley in the course of its formation, should not have 

 been sooner recognized. Similarly situated moraines extend 

 from the lips of every Yosemite wherever the ground admits of 

 their deposition and retention. In Hetch-Hetchy and other 

 smaller and younger Yosemites of the upper Merced, the as- 



