LOCATION: Circles the Black Mountain Wilderness, about 30 miles northwest of Barstow. San Bernardino County.

HIGHLIGHTS: You'll drive through a rainbow-colored basin on your way to the Black Mountain area, which has one of the largest concentrations of Native American petroglyphs in the Mojave Desert. Though vandalized, Inscription Canyon has an array of petroglyphs—about 1,000 of them, created over the last 12,000 years—as does Black Canyon. The mysterious figures include drawings of circles, rays, zigzags, wavy lines and other shapes. A common figure is a circle with a line through it from top to bottom. Some contain images of bighorn sheep, deer, reptiles, birds, insects, plants and trees. Others represent stick and solid body images of humanlike figures along with various baskets, masks and shields. Watch for endangered desert tortoises, which venture onto roads.

DIFFICULTY: Easy. There are many roads out here, and numbers on the signposts don't always match those on the BLM maps. A tip: Stay close to the base of the mountains, until you turn into the mountains at Inscription Canyon.

TIME & DISTANCE: 5–6 hours; about 67 miles.

MAPS: ACSC's San Bernardino Region. BLM's Cuddeback Lake Desert Access Guide (G–J, 4–6). CRRA, pp. 104 (A–B, 4–6) and 95 (F–H, 9–12).

INFORMATION: BLM's Barstow Field Office.

GETTING THERE: From Main Street in Barstow, turn north onto First Street. Drive over the railroad tracks and the Mojave River. Turn left onto Irwin Road. Follow Irwin Road for 5.9 miles. Turn left onto Fossil Bed Road (EF401) [N35°59.004' W116°59.995'], toward Rainbow Basin and Owl Canyon campground. Mileages begin here, so zero your odometer.

REST STOPS: The fee campground at Owl Canyon in Rainbow Basin has water. Barstow has all services.

THE DRIVE: At mile 2.9 [N35°00.477' W117°02.458'] is the turnoff for the 4-mile loop through colorful Rainbow Basin, eroded sediments noted for fossils of mastodons, early pronghorns, camels and three-toed horses. I recommend the loop. It returns you to Fossil Bed Road 0.7 miles farther northwest from the starting point. When you return to Fossil Bed Road, zero your odometer.

Continuing northwest and then west on Fossil Bed Road, you will pass a farm south of the road; nearby a rock structure of some sort, akin to a well, will be on the north side of the road. To the north is Black Mountain Wilderness.

At mile 11.4 from the Rainbow Basin loop exit (2.8 miles from the well), turn right (north) onto an unsigned road [N35°04.963' W117°14.853']. (If you miss it, 0.7 mile farther turn right onto road EF373. Follow it north, passing a lone salt cedar tree, for 2.5 miles, then angle right, into Black Canyon.) Follow the unsigned road north for 2.6 miles along the western edge of the wilderness. When you reach a T junction [N35°07.215' W117°15.373'] you'll be at the mouth of Black Canyon. Zero or note your odometer here.

Turn right, into the canyon, where you can view terrific petroglyphs on the roadside rocks. The road runs along the western and northern base of Black Mountain. Bear right at the junction [N35°11.086' W117°13.391'] about 6 miles from where you entered Black Canyon. At mile 9.1 you will arrive at Inscription Canyon [N35°11.922' W117°11.596']. The 200-yard-long arroyo is lined with petroglyphs, thought to have been created by Kawaiisu or Southern Paiute shamans.

Zero or note your odometer at the parking area, and take the small two-track that climbs south from the parking area onto a bench via Opal Mountain Road (C297). Cross a flat, drive over a pass, and follow C297 along the west side of Opal Mountain, and along the eastern boundary of Black Mountain Wilderness. Opal Mountain Road descends to a junction with road C099 at mile 10.8 [N35°04.573' W117°08.862']. Bear right, and C099 connects with EF401 in 1.2 miles [N35°03.626' W117°09.630']. There, turn left (southeast) to return to Irwin Road and Barstow.