[Joseph] Le Conte
the entire region above Yosemite & as far down as the bottom of Yosemite, has scarcely been touched by any other denudation than that of ice Perhaps all of the post glacial denudation of every kind would not average an inch in depth for the whole region Yosemite & Hetch Hetchy are lake basins filled with sand, & the matter of Moraines washed from the upper canons, the Yosemite ice in escaping from the Yosemite basin was compelled to follow upward a considerable height on both sides of the bottom walls of the valley. The canon below the valley is very crooked & very narrow, & the Yosemite glacier flowed across all of its crooks & high above its walls without paying any compliance to it thus the light-lines show the direction [drawing with writing] of ice current In going up any of the prin- cipal Yosem streams. lakes in all stages of decay are found in great abundance, regularly becoming younger untill we reach the almost countless gems of the summits with scarce an inch of care upon their shallow sandy borders, & with their bottoms still bright with the polish of ice, Upon the Nevada & its branches there is not fewer than a hundred of these glacial lakes from a mile to a hundred yds in diameter with countless glistering pondlets not much larger than moons All of the grand fir forests about the valley are planted upon moraines, & from any of the mtn tops the shape & extent of the neighboring moraines may always be surely determined by the firs growing upon them some pines will grow upon shallow sand & crumbling granite but those luxuriant forests of the silver firs are always upon a generous bed of glacial drift. I discovered a moraine with smooth pebbles upon the shoulder of the South Dome & upon every part of the Yosemite upper & lower walls level enough to hold moraines. I am surprised to find that water has had so little to do with mountain structure here. Whitney says that there is no proof that glaciers ever flowed in this valley yet its walls have not been eroded to the depth of an inch since the ice left it & glacial action is glaringly apparent many miles below John Muir
1871 Dec 17
Original letter dimensions unknown.
Reel 02, Image 0623
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