Welcome aboard, ""binaryOrbit"! Hope you can find what your looking for here!
My first thought about your question was Pedernales State Park. I'm not really interested in primitive camping (see avator

) but I do like to hike the parks we visit. Pedernales has the best hike-in/primitive camping that I've seen. A lot of it has to do with the fact that the park is so remote to begin with. Great place if you like dark skies at night and quiet (except on mild weekends). I can't think of another park that has what your looking for but there may be some out there.
Hope you can find what you need. Again, welcome to Wild Texas and,
Happy Camping!
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Turn Key, DW and Pepsi & Cherry, The Camping Boston Terriers
'03 Chevy 2500HD, 4X4, X-Cab, Long Bed
'04 K-Z "Durango", 275RK ("Sunday Haus II")
Twin Kayaks, "The Ride" by Wilderness Systems
North Central Texas, Where The West Begins!