Anza-Borrego Mud Caves Guide

One of my favorite places to explore in Anza-Borrego Desert State Park is the mud caves. Located in the Carrizo Badlands area of the park, the Anza-Borrego mud caves offer a thrilling underground adventure in the rugged and harsh terrain of the Southern California desert. In this guide, I’ll explain a bit about the caves and how to get there, and also offer a note of caution–explore these caves carefully and at your own risk.

What are the Anza-Borrego mud caves?

The Anza-Borrego mud caves were formed over the course of thousands of years as a result of water erosion on the soft mudstone in the area. The rainwater would seep into the cracks and crevices in the rock, slowly widening them and creating a maze of caves.

The mudstone is part of a larger rock formation called the Borrego Formation, which was deposited around 5 million years ago during intense volcanic activity in the area. The Anza-Borrego mud caves are a fascinating example of pseudo-karst, a type of karst landscape that is not formed from the dissolution of soluble rock, but rather from the erosion of other types of rock.

In the case of the mud caves, the soft sedimentary rocks and clay were slowly eroded over time by water, creating a network of caves and tunnels. Although the mud caves share some similarities with true karst landscapes, such as limestone caves and sinkholes, they are formed through a different geological process.

How many caves are there?

The Anza-Borrego mud caves are an expansive network of caves and tunnels formed from soft sedimentary rocks and clay. The caves are a popular destination for outdoor enthusiasts, with at least 22 caves to explore, some up to 1,000 feet (300 m) in length and 80 feet (24 m) in height. Many of the caves are easily accessible, making them an excellent choice for those seeking an underground adventure.

Some of the notable caves found in the Anza-Borrego mud caves network include:

• Big Mud Cave, the only cave marked on most maps.
• Hidden Cave, which is difficult to find without precise directions. Chasm Cave, is a popular cave with a beautiful skylight.
• Carey’s Big Mud Cave, the largest cave in the arroyo.
• Plunge Pool Cave, a short cave that ends in a spectacular round room that towers above you.
• Dip Slope Cave, which is easy to miss due to its small entrance.

Each of these caves offers a unique and exciting experience for those willing to explore them.

Getting to Anza-Borrego Mud Caves

The Mud Caves are located in the southern central portion of Anza-Borrego Desert State Park along Arroyo Tapiado, a long wash, surrounded by steep canyon walls. ​​Arroyo Tapiado winds its way through rugged terrain, dotted with towering sandstone formations and canyons.

The road is made of loose sand and gravel, and it’s not uncommon for drivers to encounter deep ruts, rocks, and washouts along the way. And while it isn’t for the faint-hearted, a decent all-wheel-drive SUV with some clearance can typically make its way to the mud caves. That said, beware after rains as it can be muddy and sand can shift around making it easy to get stuck.

In the video below, from my overlanding YouTube channel, we made a stop at the mud caves:

The backcountry trek to the mud caves begins along the S2, also known dramatically as the Great Overland Stage Route, a road that runs north-south, along the western side of the park. At GPS coordinates 32.915352, -116.240826, turn onto Vallecito Creek Road, and head northeast.

After around 2,000 feet, continue to the right into Canebrake wash and continue for about 2 miles, where you will bear right (heading southeast) at the fork. Continue for another two miles until you come to a fork, where you bear left onto Arroyo Tapiado. Follow Arroyo Tapiado north for around 2.8 miles where it will enter a tight canyon and you will be in the vicinity of the mud caves.

To find the caves, look for holes in the side of the canyon or explore some of the slot canyons that branch off from the main canyon.

Safety

The Anza-Borrego mud caves are a potentially dangerous environment, and anyone seeking to explore them should take the necessary precautions to ensure their safety. It’s critical to never explore the caves alone, as several individuals have lost their lives within their chambers. Be sure to bring adequate lighting, as the caves can be pitch black, and keep in mind that phone coverage in the area may be unreliable.

To avoid injury or worse, it’s wise to wear a hard hat or helmet, and bring multiple light sources and plenty of water. Always use caution when exploring the caves and never enter them if it has rained recently or if rain is expected. Utilizing the buddy system can help prevent injury or the need for emergency rescue.

More generally, the caves are in the desert, so you’ll want to be equipped for desert travel.

When exploring the Anza-Borrego mud caves, it’s also important to respect the environment and avoid walking on top of the caves, along the ridges, or in areas where the ground may be unstable. The hills in this region are primarily composed of mud and can be unpredictable, so staying on marked trails and using caution is critical to your safety.

Nearby Camping

There are a couple of established campgrounds in the general vicinity of the mud caves, including Agua Caliente Campground, Mountain Palm Springs Campground, and Blair Valley Campground. Anza-Borrego also allows dispersed camping.

If you are into off-roading, you might want to also hit Diablo Drop Off, which isn’t too far from the mud caves.

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