Ramble with map and compass amid the tortured landscape of Palm Wash in Anza-Borrego Desert State Park.

Thousands of years of cutting and polishing by flash floods and winds have produced the intricate rock formations and slot-like ravines you'll discover at the foot of the Santa Rosa Mountains in far-eastern San Diego County. For a mental as well as physical challenge, try this seven-mile hike through and across the labyrinth of sharp-cut desert gorges known as Palm Wash. Betwixt these dry and foreboding trenches, you'll traverse a rocky flat inscribed with enigmatic pathways that may have borne the foot traffic of Native Americans two or more centuries ago. Barring any anticipated mental confusion (i.e., getting lost), budget no less than four to five hours of time for this adventure. Short stretches of hand-and-toe climbing may be required, depending on your exact route.

Park your two-wheel-drive vehicle in the north-side turnout at mile 38.0 along Highway S-22, 19 miles east of Borrego Springs. Walk 0.1 mile east on the highway to the Calcite Mine jeep road, and start walking down the severely eroded roadbed. Dip into and out of the North Fork of Palm Wash and continue northwest. At 0.8 mile from Highway S-22, take the right fork road and descend to the sandy floor of Palm Wash. (If you have a nimble, high-clearance four-wheel-drive vehicle and can make it this far on wheels, then your hike is reduced to only 5 miles round trip.)

Now, walk up-canyon (northwest) through the vertical-walled main gorge of Palm Wash, past fallen blocks of tan-colored sandstone. The canyon walls seem to be in a state of arrested collapse, with huge slices of rock fully separated from the walls, ready to surrender to gravity during the next earthquake or flash flood. At a point about one half-mile up the canyon, a steep-walled tributary ravine on the left spills its virtual runoff into the main Palm Wash. A five-minute scramble up this constricted tributary reveals the effects of scouring by sand-laden floodwaters.

Back in the main wash, work your way over sand and soft sandstone blocks until you reach a huge, rounded granitic boulder that blocks further easy progress up the vertical-walled canyon ahead. If you're agoraphobic, quit now and return the way you came. If you're not, back up a bit and find one of at least two well-trod routes up the broken cliffs to the east. Up top there is a distinctly "rim of the world" sense, your gaze taking in the broad sweep of the southern Santa Rosa Mountains in the north and the endlessly convoluted Borrego Badlands to the south. On a sloping plateau a bit farther uphill, you can pick up a faint, intermittent trail leading generally northeast -- ultimately to the Sheep Tanks in the North Fork of Palm Wash, about one mile away.

The Sheep Tanks are good examples of the natural pockets of water called tinajas found throughout the Southwestern desert. This group has a total capacity equal to most backyard swimming pools -- about 20,000 gallons -- and plays an important role in sustaining the local population of bighorn sheep. You'll probably stumble upon (hopefully not into) the tanks from above, where they can be cautiously viewed at the gloomy bottom of a slot-like trench.

A series of sloping sandstone ledges leads down the south wall of the slotlike trench to the outlet of the lowest tank. Below that are tire tracks leading to the North Fork of Palm Wash. The rest of the trek is straightforward: walk down North Fork to where it joins the main Palm Wash and make a sharp right. Continue up-canyon toward the point where you first descended into Palm Wash, and return to the highway on the Calcite Mine road.

A topographic map, and the knowledge of using one, is highly recommended for the traverse from Palm Wash to Sheep Tanks. The Anza-Borrego Desert State Park's visitors' center in Borrego Springs is a good place to obtain one.