National Geographic : 1937 Mar
CRATER LAKE AND YOSEMITE THROUGH THE AGES accomplished re markable results. It obliterated the sharp turns of the Merced River. The jagged edges of the narrow canyon were worn off. Scouring its path, the rock shod ice carved the steep north ern face of Half Dome (page 330), and created hanging valleys from which today beautiful water falls pour forth and leap into the master stream far below. Twice again glaciers visited Yosemite Valley. During the last stage the terminal margin of the ice lay just west of El Capitan (Plate VII, upper). The valley was deep ened and the steep walls were resmoothed and repolished. The vegetation at this time, ap- 343 / Photograph from M. Hall McAllister EVEN WITH HANDRAILS IT'S A HARD CLIMB To reach the top of Half Dome, 8,852 feet, hikers in rubber-soled shoes toil up a trail of zigzag steps cut in the smooth granite, then pull themselves up the last 300 yards by cables strung on firmly anchored posts. If the scaling equipment were not removed each autumn, it would be swept away by snow avalanches. proximately 20, 000 years ago, consisted in the main of types now growing there. Pine, fir, and the giant sequoia flourished. With the disappearance of the last Yo semite glacier a beautiful lake came into existence. Had the ice left a higher barrier, this ancient Lake Yosemite might have re mained to grace the valley today (Plate VII, lower). THUS NATURE FASHIONED A SCENE OF IMPRESSIVE GRANDEUR No major change has since affected the landscape. A scene of impressive grandeur awaits the visitor. Early belief that Yosemite Valley was the result of some catastrophic dislocation of the earth's crust is no longer accepted. Instead, Yosemite's long record, when rightly read, shows that changes in eleva tion, and the slow but persistent work of running water and moving ice have wrought the marvel. A visit to Yosemite National Park com pels at least an hour of meditation and reverence at Inspiration Point. Here the artist set his easel and translated to canvas the geologic story of Yosemite. From this point of vantage, it is not hard for the imaginative visitor to transcend the barrier of time and to slip eons back into geologic history. By so doing he may visualize the land scapes of Yosemite's past and comprehend the wonders of earth history that Nature has recorded.