386 Adventures in Scenery 



Approach to Yosemite National Park 



through Canyon of Merced River 



Stanislaus River is crossed seven miles beyond Manteca, at 

 Ripon, and 16 miles farther is Modesto and Tuolumne River. 

 From Modesto it is possible to select another route to Yosemite 

 National Park, but the classic and most desirable route is across 

 the flat valley floor to Turlock and Merced (133 miles) . From 

 Merced the all-year highway up the canyon of Merced River 

 offers an unparalleled approach to Yosemite entrance at El 

 Portal (199 miles). This is the approach par excellence to 

 Yosemite National Park. 



Old Roof Rocks of Granitic Batholith 



Exposed in Merced Canyon 



After leaving Merced the rocks making up the foothills 

 as far west as Bagley belong to the Mariposa formation (of 

 Jurassic age) . Beyond Bagley to El Portal is a belt of older 

 rocks, the Calaveras formation. These are the ancient for- 

 mations that once extended far over the Sierra slope, but since 

 the upheaval of that great range have been largely eroded and 

 worn away. These are the remnants of the roof rocks which 

 were uplifted when the great granitic batholith which is the 

 core and body of the Sierra Range was forced up as a hot 

 molten mass under them. The rocks are highly metamorphosed, 

 upturned, bent and folded. The two formations extend far 

 along the lower western slope of the Sierra Nevada. 



Calaveras Formation Crossed between 



Bagley and El Portal 



The rocks of the Calaveras formation form a belt along the 

 lower Sierra slope. Across this belt the Merced River has cut 

 its canyon. The highway follows the course of Merced Canyon. 

 From the vicinity of Bagley to El Portal, a distance of about 

 30 miles, the highly metamorphosed and contorted rocks of 

 the Calaveras formation are on either side of the canyon. The 

 rocks are composed mostly of upturned beds of slate, quartzite, 



