As defined by the United States Geological Survey, the canyon begins at Glen Aulin and ends directly above Hetch Hetchy Valley.

The flora of the valley bottom is a haphazard melange of chaparral, manzanita scrub and oak woodland[2] characteristic of the foothills and lowlands with a coniferous forest reminiscent of (but different from) that found above the canyon rim.

Perhaps the greatest of these is 800-foot (240 m) Waterwheel Falls, named for a dramatic circular plume of water that appears when the river and the winds run high.

White Wolf campground, southeast of Hetch Hetchy Reservoir, is within day-hiking distance of the canyon rim, but the return trip from the very bottom is long and steep.

Between the eastern tip of the reservoir and the point where the trail begins the climb to White Wolf, the valley is a trackless wilderness.