I noticed that the Wichita Mountains Wildlife Refuge is open with some closures currently. This area is VAST and has tons of area for hiking/fishing for those in the North Texas/Southern Oklahoma looking to get out of the house and at least enjoy some nature.
We went last Monday and it was amazing!! There is no camping currently there but there is camping near Lawton which is only a short distance away.
I suggest checking out the Prairie Dog City for some great wildlife, the holy city for a brief walk around a cool historic site and the Tower trail for a good little easy hike with some great views. Mount Scott, the highest point in the park is open for both hiking and driving up so if you want to get out and really explore go there!! The visitor center is closed and one loop area but plenty to do while still distancing!!