From the Guidebook:
Long ago, Mohave Indians
used a network of pathways to cross the Mojave Desert.
In 1826, American trapper Jedediah Smith used their paths
and became the first non-Indian to reach the California
coast overland from mid-America. The paths were worked
into a military wagon road in 1859. This "Mojave
Road" remained a major link between Los Angeles and
points east until a railway crossed the desert in 1885.