Rainbow Basin is reached by driving 6 miles along the busy Irwin Road
, which heads out of town to the northeast and ends at the main gate of the Fort Irwin Military Reservation, part of a vast complex that occupies hundreds of square miles at the centre of the Mojave, then by turning left along the Fossil Bed Road
for another 3 miles. This is a good quality gravel track that later curves back south and meets CA 58. A signposted right turn to the basin soon forks - right is to the small Owl Canyon campground ($6 per night) while left is a one-way loop through the basin. A notice warns 'No RVs or Trailers' but the drive is in fact suitable for all vehicles. It follows beside then partly along a dry wash, cuts left over some sandy mounds then returns down another ravine to the Fossil Bed Road. Upstream, the wash splits into many branches, all of which end quite soon at the base of eroded mudstone cliffs and sometimes have deep, narrow places, and even small caves. The cliffs and the surrounding badlands are composed of a mixture of colours of rock and sand - reds, pinks and browns, with scattered veins of white gypsum crystals. They also occasionally contain fossil bones, and the remains of a variety of dinosaurs have been unearthed here over the years.
Camping is not allowed along the scenic drive, but there are many (free) alternatives to the official campsite along dirt tracks that lead into the nearby desert. The surrounding area is quiet and peaceful, with the silence broken only by occasional distant explosions and gunfire from the army base over the hills to the east.