The park is open, and is open for swiming. However you will need to make a reservation through the Texas Parks and Wildlife website. We were there two days ago. We tried to make another reservation yesterday but they were booked. Earliest we could get was July 18th.
You can not enter the park unless you purchase your passes on line in advance, yes there is swimming.. last I heard.
I would call first to be sure. If they are open you will have to social distance and once the park is full, they stop letting people buy day passes
I think so.
Thanks! Your answer is awaiting moderation.