Studies in the Sierra 



187 



had been partially separated in crossing the divide, and receiv- 

 ing a swift-flowing affluent from the fountains of Cathedral 

 Peak, it set forth again with renewed vigor, pouring its mas- 

 sive floods over the southwestern rim of the basin in a series of 

 splendid cascades; then, crushing heavily against the ridge of 

 Clouds Rest, curved toward the west, quickened its pace, focal- 

 ized its wavering currents, and bore down upon Yosemite with 

 its whole concentrated energy. Toward the end of the ice-peri- 

 od, and while the upper tributaries of its Hoffmann companion 

 continued to grind rock-meal for coming forests, the whole 

 body of Tenaya became torpid, withering simultaneously from 

 end to end, instead of dying gradually from the foot upward. 

 Its upper portion separated into long parallel strips extending 

 between the Tenaya basin and Tuolumne mer de glace. These, 

 together with the shallow ice-clouds of the lake-basin, melted 

 rapidly, exposing broad areas of rolling rock-waves and glossy 

 pavements, on whose channelless surface water ran everywhere 

 wild and free. There are no very extensive morainal accumu- 

 lations of any sort in the basin. The largest occur on the divide, 

 near the Big Tuolumne Meadows, and on the sloping ground 

 northwest of Lake Tenaya.* 



For a distance of six miles from its mouth the pathway of this 

 noble glacier is a simple trough from 2000 to 3000 feet deep, 

 countersunk in the solid granite, with sides inclined at angles 

 with the horizon of from thirty to fifty degrees. Above this its 

 grand simplicity is interrupted by huge moutoneed ridges ex- 

 tending in the general direction of its length over into the basin 

 of Lake Tenaya. Passing these, and crossing the bright glacial 

 pavements that border the lake, we find another series of ridges, 

 from 500 to 1200 feet in height, extending over the divide to 

 the ancient Tuolumne ice- fountain. Their bare moutoneed forms 

 and polished surfaces indicate that they were overswept, exist- 

 ing at first as mere boulders beneath the mighty glacier that 



* Because the main trunk died almost simultaneously throughout its whole ex- 

 tent, we, of course, find no terminal moraines curved across its channels; nor, since 

 its banks were in most places too steeply inclined for their disposition, do we find 

 much of the two laterals. One of the first Tenaya glacierets was developed in the 

 shadow of Yosemite Half Dome. Others were formed along the bases of Coliseum 

 Peak, and the long, precipitous walls extending from near Lake Tenaya to the Big 

 Tuolumne Meadows. The latter, on account of the uniformity and continuity of 

 their protecting shadows, formed moraines of considerable length and regularity, 

 that are liable to be mistaken for portions of the left lateral moraine of the main 

 glacier. 



