Fish Creek Wash is the gateway to a fascinating labyrinth of rugged canyons, twisted arroyos, and mud hills covering the stark and desiccated Carrizo Badlands in a remote corner of Anza-Borrego Desert State Park. Why the name Fish Creek for a sand-filled desert wash mostly devoid of water? Apparently this was once a sluggish creek strewn with large potholes — some containing desert pupfish — worn into its bedrock floor. A huge flood in 1916, it is surmised, smothered the creekbed with a thick coating of sand and destroyed the habitat for the fish.

Today’s Fish Creek supports only scattered smoke trees, desert lavender, mesquite, and other shrubs, plus a sporadic stream of travelers by foot, off-road vehicle, and bike. Over a distance of about 13 miles, the wide, nearly flat floor of the wash ascends some 1000 feet of elevation, a rather easy-going gradient for an out (uphill) and back (downhill) trek by means of riding a mountain bike. However, soft sand here and there may make the ride strenuous and a bit frustrating at times. Muddy conditions following a heavy rain could make forward momentum a messy and glacially slow process, and that goes for motor vehicles as well. The ground is firmest when it is only slightly damp — a not uncommon situation in February and March.

To get to the starting point, drive east on Highway 78 to the desert town of Ocotillo Wells, then go eight miles south on the paved Split Mountain Road to the dirt-road turnoff for Fish Creek Primitive Camp. That turnoff is where you can start riding your fat-tire bike. Be sure to bring along copious quantities of water, especially if the weather is warm.

By the time you’ve passed the primitive campground, the portals of Split Mountain loom on both sides. There, the waters of Fish Creek Wash (during many floods over geologic time) have worn their way through a fault zone, creating sheer walls on both sides. Don’t miss, on the right, just before the walls of Split Mountain begin to part, a spectacular anticline (an inverted “U”) of sandstone layers embedded in the canyon wall.

Next comes a landscape dominated by “mud hills” strewn with sparkling chips of gypsum crystal. Stick with riding on the main Fish Creek route, and don’t ride in areas not open to motor vehicles. Off-trail exploration is allowed in the state wilderness zones surrounding Fish Creek, but only on foot.

Work your way gradually upward — if you have the strength and determination — all the way to the confluence of Sandstone Canyon, some 13 miles from the pavement of Split Mountain Road. The Fish Creek route continues north, but through less-interesting terrain ahead, so this a good place to turn around and take advantage of a modest assist from gravity on the return.

This article contains information about a publicly owned recreation or wilderness area. Trails and pathways are not necessarily marked. Conditions can change rapidly. Hikers should be properly equipped and have safety and navigational skills. The Reader and Jerry Schad assume no responsibility for any adverse experience.

Fish Creek mountain-bike ride
Explore Anza-Borrego’s Split Mountain and Fish Creek Wash on self-propelled wheels.
Distance from downtown San Diego: 102 miles
Biking length: 26 miles round-trip
Difficulty: Strenuous