64 



YOSEMITE NATURE NOTES 



A BRIEF STORY OF YOSEMITE 



Yoscmite National Park, one of our 28 

 scenic and scientific national parks and 

 one of some iso areas administered by 

 the National Park Service, is world fam- 

 ous for the scenic grandeur of Yosemite 

 Valley and its high Sierra country. It 

 embraces about 1200 square miles with 

 elevations ranging from foothills to al- 

 pine peaks over 13,000' high. Such differ- 

 ences in elevation account for the zone- 

 like distribution of the 17 evergreens and 

 18 broad-leaf trees making up Yosemite's 

 forests and to a degree its wildlife also. 

 Deer are especially abundant in Yosemite 

 Valley where they, with the bear, are 

 often mistaken for tame animals. They 

 are dangerous and park regulations for- 

 bid feeding them in the park. 



Yosemite Valley was probably discov- 

 ered by William Penn Abrams in 1849 

 during the gold rush days. It later came 

 into national prominence through the 

 185 5 reports of Dr. Lafayette H. Bun- 

 nell of the Mariposa Battalion under 

 Major James D. Savage, and the extended 

 writings of James M. Hutchings, John 

 Muir, Starr King and many others who 

 worked for its preservation. Because of 

 growing public interest, John Conness, 

 Senator from California, introduced into 

 the Congress in 1864 a bill to set aside 

 Yosemite Valley and the Mariposa Grove 

 of Big Trees as the Yosemite Grant. The 

 bill was passed and signed by President 

 Abraham Lincoln. Here was the first 

 practical application of what was to 

 grow into our great National Park Sys- 

 tem of today. It was given to the State 

 of California to administer until 190 5 

 when it was receded to the federal gov- 

 ernment for incorporation in Yosemite 

 National Park which had been established 

 in the surrounding country by Congress 

 in 1890. Yosemite National Park was 

 first administered by the U. S. Army 

 but with the establishment of the Na- 

 tional Park Service as a bureau of the 



U. S. Department of the Interior in 

 1916, administration passed to civilian 

 hands. Today the visitors' contacts with 

 this Service are largely through uni- 

 formed park rangers and naturalists, 

 whose duties are to protect, preserve and 

 interpret the park under the supervision 

 of the park superintendent. 



The story of the formation of Yosem- 

 ite Valley goes back some two hundred 

 million years when this land was beneath 

 the sea. As it subsequently arose out of 

 the sea it was covered with layers of 

 sediments many thousands of feet thick, 

 the remnants of which are seen today as 

 greatly changed rocks in the foothills 

 and on some of the park's highest peaks. 

 The granites which now make up most 

 of Yosemite National Park's rocks welled 

 up underneath this old sea deposit as 

 molten rock which cooled slowly as the 

 sea deposits eroded away. As the Sierra 

 tilted westward through three stages of 

 uplift, rivers established courses down 

 this slope wearing successively deeper 

 valleys into the granite. About one mil- 

 lion years ago the third and last deep and 

 steepsided "V"-shaped river valley was 

 invaded at separate times by three ice 

 age glaciers which carved the valley into 

 its present "U"-shaped form. The first 

 two glaciers were 3000 to 4000 feet deep 

 and extended as far as El Portal. The 

 third and last glacier, filling only about 

 a third of the depth of the valley, drop- 

 ped its load of rocks and debris at a point 

 between El Capitan and Bridalveil Fall. 

 This made a dam which backed up the 

 water from the melting ice to form 

 Ancient Lake Yosemite, 5*2 miles long 

 and perhaps as much as two thousand 

 feet deep in the area of Camp Curry. As 

 the lake filled with sediment the present 

 level floor of the valley came into being. 



The first tourist party came to Yo- 

 semite Valley in 185 5 on horseback over 

 old Indian trails. It was not until 1874 



