The Skull Rock Nature Loop passes through a spectacular maze of massive rock formations, rolling hills and richly-lined washes. Rock in this area began as liquid molten deep below the earth's surface. Continuously heated by movements in the Earth's crust, this molten oozed upward and cooled while still below the surface. Subsequent surface layer erosion exposed the rock, a form of granite called Monzogranite.

The sticky nature of the rock and countless cracks make Joshua Tree a climber's paradise

As ground water percolated down through the monzogranite’s joint fractures, it began to transform some hard mineral grains along its path into soft clay, while it loosened and freed grains resistant to solution

The Skull Rock Nature Loop passes through mid and high mojave desert ecotones

Skull Rock

Granite formations eventually break down forming new soil from which desert flora can grow

Made primarily of granite, the Jumbo rocks began as underground molten rock and eventually exposed to air and erosion and hardening to its present form

A lone Joshua Tree soaks up the sun adjacent to the Skull Rock Trail

Erosion continues to sculpt rocks into interesting formations

Some formations beg for exploration but watch where you place your hands - 6 native rattlesnake species live in Joshua Tree

The Skull Rock Trail passes through the Jumbo Rocks area, known for its large and unusual rock formations

Creosote, Mojave yucca and juniper trees dominate the Skull Rock / Jumbo Rocks area