Look into the Hot Springs and Fort Smith areas, near Ouachita National Forest and Ozark National Forest. Years ago we went out there, very cool area. The closer to OK the better to get to some mountain overlooks. Very pretty.
Just a thought, you could plan for a big trip to Big Bend in TX in the Fall/Winter. My Dad, uncle and I went out there when I was a kid. Get reservations, you can’t just show up since a lot of areas are off limits.
Camping in TX is miserable in the Summer, I wouldn’t recommend it. LOL