Rainbow Basin, National Natural Landmark in San Bernardino County, California.

Rainbow Basin is a protected natural area in the Mojave Desert featuring colorful sedimentary rock formations in shades of red, gray, pale green, and tan. The landscape displays steep bluffs and layered ridges that reveal different geological periods through their exposed strata.

The basin contains fossil beds from roughly 12 to 16 million years ago during the Miocene epoch. These deposits preserve remains of extinct camels, horses, and mastodons that once lived in a wetter climate than today.

Scientists and geology students examine the site for educational purposes, studying rock formations and analyzing different visible strata in the landscape.

The area is accessible via a loop road extending about 3.7 miles (6 km) from Barstow that winds through the colored formations. A nearby campground offers basic facilities for visitors who want to stay overnight in the desert.

After heavy rains, the normally dry basin transforms as water cascades through the rock formations, creating temporary waterfalls in the desert. This rare sight happens only when rain is sufficient, making it a memorable moment for visitors who encounter it.