DandyDon:I'd suggest calling the park: 432-375-2370, to make sure the weekend chosen would not be one when they drained the pool for cleaning or something. It might be good to call the adjacent dive shop: 432-375-2572 to ensure that they will be on hand for air fills.
PM me if I can help in with any inforation or anything.
That's a good point Don! The Park Rangers usually close the pool for a short period in the January - February time frame to drain the pool and clean it out. It would definitely be advantageous to call ahead of time and verify that they aren't going to be cleaning the pool during the weekend that you plan on going.