I've looked for years but gave up. You cannot ride ATVs inside the park. Even on the dirt roads and Jeep trails the vehicle has to be street legal.
The closest thing I have heard of is 30 miles outside of Ozona called the Escondido Draw Recreational Area.
It is 3400 acres, that at one time was going to be run by the state parks dept. but now looks like it's controlled by the Texas Motorized Trail Coalition.
I can't really tell if this park is open to the public!
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