98 ***** "Oh, Ranger!" 



Dome. It finally pushed through and met head-on with the other glacier 

 slowly moving down the Merced Canyon. The two of them churned 

 around with billions of tons of weight behind them and finally plucked 

 and scraped at the cliffs until they carved the present walls of Yosemite 

 Valley. 



"You can find a record of what happened on those walls up there. 

 If you look closely, you will see spots where the cliffs have been polished 

 almost as smooth as the marble of a bank building. Granite does not 

 crack so smooth naturally. The glaciers, scraping away at the sides of 

 the mountain, polished that rock. That is one of the ways that Nature 

 chooses to leave her notes for men to puzzle about. Near Tenaya Lake 

 and again near Merced Lake are perfect examples of glacier polish on 

 the cliffs. 



"Here in Yosemite Valley, the biggest job of the glaciers was to 

 carve Yosemite Valley deeper and deeper. Streams had already carved a 

 deep gorge, but the glaciers made it wider. When they melted, the gorge 

 became a lake. The streams next dumped sediment into the lake and it 

 became a valley. You can see the same process happening over again, 

 on a much smaller scale, at Mirror Lake. There the streams are now 

 filling up the lake, just as they have already filled Yosemite Valley with 

 fine silt several hundred feet deep. Glacier Point, thirty-two hundred 

 feet above the valley, was left suspended by the glaciers when they 

 melted. One of Nature's little jokes was to leave a great rock suspended 

 over the cliff, almost half of it projecting over the rim. That is known 

 as Overhanging Rock." 



One of the ranger's most important jobs is telling the visitors to the 

 parks how it all happened. In all of the parks there exist phenomena of 

 Nature. These marvels were, of course, the reason for setting aside the 

 area as a national park. The visitor is not satisfied to come and look at 

 a beautiful mountain. He wants to know why it is there, what happened 

 to make it, and if it will always look as it does at the time he sees it. 

 Some of the answers to his questions are the solutions to the riddles of 

 the universe. They call for scientific explanations in simple terms which 

 the layman can understand. 



The story of the national parks, from a natural history point of 

 view, is an interesting one. In the early days many fakes were perpe 

 trated upon the unsuspecting visitor by guides ill-trained to tell of the 

 ways of Nature in the creation of the earth. Often the true answer to a 

 question was not known. So the guide told the Dude that half of Half 

 Dome was shaken down in a great earthquake. To give visitors the true 

 answers to their questions, as well as they can be read from Nature's 

 notes, a staff of ranger naturalists is found in the parks. Their business 

 is to study the mountains and their children, the glaciers, the forests, 



