These caves are estimated to be nearly 5 million years old, having been created by fluvial erosion caused during extended periods of heavy rainfall. During the rainstorms, channels are cut into the mud hills, causing erosion, which forms canyons with unstable and undercut walls. Because of the cohesive consistency of the mud in this particular area and its ability to swell to several times its original dry volume, it adheres to itself and to the canyon walls, creating natural bridges and, sometimes caves, as it dries.
These caves are said to be some of the most extensive caves of their kind in the world. It is quite possible that you will find fossils that are 1-2 million years old. The length of the caves varies, and it's impossible to tell initially if you're getting yourself into a huge cave journey or a small one. Small slits can go on forever and large openings can end shortly. There are multi-level caves, rooms with skylights, tiny crevices and areas that are 35 feet wide. A huge perk is the temperature drop in the caves.
These caves can be dangerous. People have lost their lives here. Never explore by yourself and always carry a light with you. Your phone may or may not have coverage here.
Always use caution when exploring caves. You will need to carry several light sources, and water, and it is recommended that you wear a hardhat or helmet. Never enter the caves if it is raining, has rained recently or if rain is expected. Take a caving partner with you when you explore the caves or let someone know exactly where you are going to be and when you will return. Use the buddy system!
Do not walk on top of the caves, along the ridges or in areas where the ground may cave in. These hills are made of mud and can be very unstable.
Personal Experience: I cannot stress enough the importance of what time you go (go during cooler months) and how crucial it is to be extremely prepared. I was shocked by how many parents I saw out here with their small children. This is not safe and I do not recommend bringing kids! These are caves that are literally made out of hardened mud, which are collapsing constantly! When and where it will crumble, no one knows. You just want to pray that you are not below it when it happens.
Bring a lot of water if you go out here. Come prepared with food, flashlights (the caves are pitch black if you go deep enough), huge bonus points for head protection (helmet), candles if you want to light the caves, a phone (keep it off unless you need to use it because it will get drained fast out here.
Even still, you may or may not have service).....and then all other normal desert-preparedness gear. We camped out right in the heart of where the caves are, under the stars, planets & the milky way. It was awesome! We explored minimally inside the caves though because I did not sense this area to be very safe.
We arrived near sunset. After unpacking we did a little exploring at night. It was truly a surreal experience. It felt like we were on Mars. It was seriously so much fun just walking on the outskirts of the caves at night. This area holds many ancient, spiritual and devastating secrets--you can just feel it. Be respectful when you are out here. Leave no evidence that you were ever here. Respect the desert, because it damn well has earned it. This whole area was under water at one point. Oceanic fossils can be found. Look around and imagine swimming at the top of these caves. Unbelievable!
You can also sense all the tragedies out here. With all the mysterious allure also comes darkness. There have been many deaths and great injuries out here undoubtedly. Be very certain you should be exploring the deep desert before you decide to head out here. You will be surrounded by nothing but desert land for as far as the eye can see. You do not want to become a statistic. The desert is no joke. Often enough you will hear about people going missing out here, having a horrible accident or getting stuck out in the middle of nowhere with no phone service. Do not let that be you!
Make sure you have lighting for inside the caves. Helmets with a headlamp are highly encouraged. We obviously did not have helmetsWe arrived with an hour or so left of sunlight. Most of the exploring happened the next day, but we had quite a lot of fun in the nighttime too.The next morning after a beautiful sleep we made some delicious, hearty food: catfish with sauteed veggies, hard-boiled eggs & fresh-squeezed orange/grapefruit/pineapple juice, yum! I'm a big believer in tasty food while camping. Gotta get those nutrients!
We spotted some guys climbing to the top. I believe this is how a guy died last year, doing this exact same thing when the hill crumbled below him, falling into a cave and suffocating to death. Be smart!