Mud Caves (Arroyo Tapiado)

These caves are underground slot canyons in the Anza Borrego Desert. The caves / canyons are excavated by water flowing through the desert mudstone (which is softer than sandstone). The mud is dry, so you won't get muddy but you will get VERY dusty. Caves are especially dangerous after rain, as the mudstone can get soft and collapse, so is better to avoid them if it rained recently or rain is in the forecast. In summer the desert is scorching hot, so these caves are better visited Fall, Winter or Spring. Especially good is February-March, as the desert gets covered in wildflowers (in good rain years). Status of the wildflower bloom is available here: Recommended gear:

The drive through Vallecito road is almost always passable with 2WD cars, but high clearance is recommended. Other roads will require 4WD.

One can do several loops hitting the most relevant caves along the way, you will find them labeled as "Route:" in the KML map. You can also download ready-to-print PDF maps based on aerial pictures for each of the routes. For more information take a look at:

Once done with the caves you may want to check out the nearby Agua Caliente Hot Springs. I think they charge $5 per vehicle for day use but some people park outside and walk in for free. They have hot and cool water pools and hot showers. Nice spot to unwind and clean up before the drive home. Pools close 5pm, reopen on Sat 6pm to 10pm but only for those that stay at the campground. You may want to stay overnight and check out more caves the next day or go check out some of the amazing slot canyons at Palm Wash or the Domelands. You may camp at the Agua Caliente Campground for a fee or you can camp for FREE anywhere else in the Anza Borrego State Park. More information on free camping spots at http://www.hikespeak.com/campgrounds/anza-borrego-desert-state-park-camping/.