See the context of this sign.

Tracking the Glaciers

Before the glaciers came, Tenaya Canyon
was a gently-sloping stream valley. Ice
reworked the scene. Grinding down from
the Sierra crest on your left, a series of
glaciers - sometimes thousands of feet
thick - widened and steepened the valley,
sheered canyon walls, and scoured and
polished granite slabs on the way past Half
Dome to Yosemite Valley. Tenaya Lake
formed in a glacier-gouged basin.

Tenaya Canyons' present "U" shape is
characteristic of glacier-carved valleys.
Look for the evidence and effects of
glaciers throughout the Yosemite area.

When the last glacier retreated, it
left behind huge, randomly scattered
boulders called glacial erratics. The
short trail below crosses a field
of erratics.

Don't miss the rest of our virtual tour of Yosemite National Park in 4116 images.