See the context of this sign.

Merced Grove Trail

The smallest of Yosemite's three giant
Sequoia groves, the Merced Grove, offers
perhaps the best opportunity for a solitary
experience among the Big Trees.

Isolated Groves

Advancing down canyons, plowing
away soil, leveling everything in their
path, glaciers drastically reduced the
Sequoias' formerly extensive range. Giant
Sequoias now grow only in isolated groves
on the Sierra's western slope.

Big Trees are also limited by their own
specialized growing needs. To germinate,
the seeds need periodic fires to expose bare
mineral soil and to burn off competing
species. Young Sequoias grow so rapidly
that each tree requires a reservoir of
moisture -- mostly from winter snowfall.

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