Rainbow Basin Natural Area is located north of Barstow, California.  It features a unique region of badlands & washes, complete w/ small slot canyons in a mix of varied-colored geology.  This small wash I followed as it went through a slot canyon, going underground for about 100 feet & then emerging to the base of this 20 foot cliff where I couldn't proceed further.  During a flash flood there would be a neat waterfall.