As others have said, this is not much more than a boondocking spot, but its one of the only places to stay within the national park and is in a very scenic part of the park with large boulders mixed in with a great diversity of cacti. This place is away from the highway, so is peaceful at night. The caretaker did not come to collect our money (100 pesos) until the next morning, but we chatted with a very friendly retired ex-pat who lives next to the park who came to greet us.
Given the options to stay north of the national park in a dumpier town and more expensive RV park, I'd stay here again any day.
Note-- there is a water faucet and trash bins, but no other services available that we could see. Best to come well-prepared and self-contained. - WinnieViews
Free overnight stop. Pretty area. No marked sites, but huge area for any size and amount of rv's. We found one water spigot that flowed to top off with. Fair sand/gravel road access. No other services. Quiet. - Brujomar
This is your basic middle of nowhere, very large gravel parking area that would hold 30-40 RVs. Pull in and park where ever. They have a small cafe and the people who ate there said the food was great. A complete dinner was Peso 50.00. It is an interesting desert area in the middle of the mountains. It is nothing more that a flat place to stop overnight on your way to somewhere else. - Luke