Into the San Joaquin flows Merced River, coming from the eastward down out of the Sierras through the famous Yosemite Valley. Most of its waters are diverted by irrigation canals leading for many miles over the floor of the broad San Joaquin Valley. The road to the Yosemite leads eastward up the slope, crosses the crest, and at Inspiration Point, fifty-six hundred feet elevation, gives the first view, then steeply descending to the river bank, it enters the western portal. Yosemite is a corruption of the Indian word "A-hom-e-tae," which means the "full-grown grizzly bear," and is supposed to have originally been the name of an Indian chief. This magnificent canyon, on the western slope of the Sierra Nevada, is a deep gorge eight miles long, traversed by Merced River, its nearly level floor being about thirty-eight hundred feet above the sea-level. The enclosing rocky and almost vertical walls rise from three thousand to five thousand feet above the river, the space between varying from a half-mile to two miles. Over the valley floor winds the beautiful green current of the diminutive Merced, bordered by trees and vegetation, the surface being generally grass-grown. The high vertical walls, the small amount of _débris_ at their foot, and the character of the Yosemite chasm itself, have led the geologists to ascribe its formation not to erosion or glacial action, but to a mighty convulsion in the granite rocks, whereby part of them subsided along lines of fault-crossing nearly at right-angles. The observer, standing on the floor, can see no outlet anywhere, the almost perpendicular walls towering on high in every direction.