The Slot formed through millennia of flash flooding. Desert storms - rare but intense - send torrents of water through the drainage, carrying sand and debris that scour the mudstone walls. The soft rock erodes easily; the channel deepens and narrows over time. The result is a slot canyon perhaps 30 feet deep and as narrow as a foot in places. Unlike sandstone slots, which display swirling 'Navajo tapestry' patterns, mudstone creates plainer walls - grays and tans, with horizontal striations marking different depositional layers. The canyon is geologically young and still forming; each flash flood reshapes the passage.

Hiking The Slot begins with a short walk across open desert wash. The canyon entrance appears suddenly - a dark slash in an otherwise undistinguished hillside. Inside, the temperature drops; the walls close in; the sky becomes a narrow ribbon overhead. Some passages require sideways shuffling; the tightest spots barely accommodate a human body. The canyon floor is sandy, sometimes with standing water after rain. The passage twists, opens occasionally into wider chambers, then narrows again. The experience lasts perhaps 30 minutes of actual canyon hiking, but the sensory contrast - from open desert to enclosed slot to open desert again - amplifies the impression.

Slot canyons are inherently dangerous during rain. Flash floods can arrive without warning, filling narrow passages with debris-laden water moving at fatal speeds. People die in slot canyons every year. The Slot at Anza-Borrego is relatively safe - the drainage is small, the canyon short - but the principle remains. Never enter any slot canyon if rain threatens, even distant rain in upstream areas. The soft mudstone walls of The Slot can also collapse; don't climb or lean against them. The passage is tight; claustrophobes may struggle. But with basic precautions and good weather, The Slot is safe for most hikers.

Anza-Borrego Desert State Park encompasses over 650,000 acres of Colorado Desert - the largest state park in California. The park preserves desert wilderness, bighorn sheep habitat, and significant paleontological sites. Slot canyons, palm oases, badlands, and wildflower displays (in wet years) draw visitors. The park allows dispersed camping and maintains few facilities - this is wilderness-style recreation. The Slot is just one of many geological features; Font's Point, Borrego Badlands, and the metal sculptures along Borrego Springs Boulevard offer additional attractions. The desert can exceed 110°F in summer; winter and spring are optimal visiting seasons.

The Slot is located off Highway 78 in Anza-Borrego Desert State Park, approximately 3 miles east of the Ocotillo Wells turnoff. The trailhead is at a dirt pullout; the hike to the slot is approximately 0.5 miles each way, mostly through sandy wash. No permit required; park entrance fees apply. The slot can be hot in summer - carry water. Wear shoes with good grip; the canyon floor can be slippery. Check weather forecasts; never enter if rain threatens. The canyon is narrow - backpacks may need to be carried rather than worn in tight sections. Borrego Springs (30 miles northwest) has lodging and restaurants. San Diego is 90 miles west.