See the context of this sign.

Indian Nomads

Seeking the warm desert in winter and the cool mountains in
summer, they camped in mud-plastered brush shelters, caves, and
natural rock shelters - near washes and jumbles of boulders, in
mesquite thickets, on shorelines of dry lakes. They know the
secrets of where to hunt desert bighorn sheep and antelope, to
capture rabbits and small rodents, and to gather nuts, beans,
acorns, fruits, grubs, insects. And they jealously guarded the
locations of the pitifully few springs and rain catchments.

Today the desert is empty of these early peoples, except for scattered
traces such as pictographs, bits of chipped stone and charred bone,
and bedrock mortars - and tales, passed on by old times, who
remember their final days.

Family bands of early Serrano, Cahulla, and Chemenuevi Indians
once ingeniously met the harsh demands of life in this desert land

Don't miss the rest of our virtual tour of Joshua Tree National Park in 1588 images.