AUTO TOUR 



79 



y CROSSING THE VALLEY ON 

 * THE POHONO ROAD. As you 



* ' start across the valley from the in- 

 tersection near Bridalveil Fall parking 

 area you will pass through a small grove 

 of trees. On the right side of the road 

 in this little grove is a marker on the 

 site where two prospectors were reported 

 killed by Indians on May 2, 1852. In- 

 dians found later wearing the prospect- 

 ors' clothing were executed by soldiers. 



Y PRESIDENT THEODORE 

 ACi ROOSEVELT AND JOHN MUIR 

 W CAMPSITE. "On this site Presi- 

 dent Theodore Roosevelt sat beside a 

 campfire with John Muir on May 17, 



1903 and talked 'forest good.' Muir 

 urged the President to work for preser- 

 vation of the priceless remnants of 

 America's wilderness. At this spot one of 

 our country's foremost conservationists 

 received great inspiration." In this 

 meadow the Mariposa Battalion also had 

 camped at the time of their entrance into 

 Yosemite Valley on March 27, 1851. It 

 was then that Dr. Lafayette H. Bunnell, 

 surgeon of the battalion, proposed the 

 name Yosemite, a corruption of 

 "O-ham'i-te" or "Oo-soo'-ma-te," (In- 

 dian f°r 'grizzly bear.') , a term he picked 

 up from the Indian guide Bunnell did 

 not know that this name applied to only 

 those Indians in the valley who lived 

 north of the river and that all the Indians 

 referred to themselves as Ahwahneeches, 

 people of Ahwahnee, the deep grassy 

 valley. 



YOSEMITE VALLEY TO WAWONA AND SOUTH ENTRANCE 



(Total driving distance 25.4 miles) 



w 



WAWONA TUNNEL The Wa- 



wona Tunnel, blasted out of granite 

 in 1933 to avoid a roadcut which 

 would deface the landscape, is four- 

 fifths of a mile long 28 feet wide and 

 19 feet high. There is a maximum of 

 5 50 feet of rock above the tunnel and 

 a maximum of 503 feet to the edge of 

 the cliff. The tunnel was drilled entirely 

 from the east side under government con- 

 tract; it took almost 2 years to complete 

 and cost $847,500. One of the amazing 

 facts is that not a single person was 

 killed or seriously injured in the con- 

 struction of this tunnel. Automatic 

 fans in the tunnel exhaust carbon mo- 

 noxide. When 1 part gas to 20,000 parts 

 of air is registered, the controls turn 

 the fans o'n low and as the ratio of car- 

 bon monoxide increases they gradually 

 increase the speed. At full speed impure 

 air is exhausted at a rate of 300,000 

 cubic feet per minute. Grade in the 

 tunnel is 5%, approaching 6% at the 

 west end. 



yy EXFOLIATION. As the road here 

 ^ passes under Turtleback Dome, it 

 ™ is cut through solid granite expos- 

 ing layers or "shells" of rock. These are 

 caused by an expansion process called 

 exfoliation, the same which has caused 

 the curved, smooth surfaces of domes 

 such as North Dome and Half Dome, 

 and the Royal Arches. The black 

 splotches in the rock are concentrations 

 of diorite, a type of granite in which 

 the dark materials (black mica and 

 hornblende) predominate. The white 

 streaks running through the rock are 

 quartz and felspar, the two light-colored 

 minerals found in granite. 



yj VIEW OF CASCADE FALLS. 



^ Just beyond the west end of the 



* tunnel you can see Cascade Falls 



on your right and on the opposite side 



of the valley. They drop about 500 



feet. 



