Appalachia Bay is about an hour and a half from you. It's on lake keystone a bit north west of Tulsa. It's an island of about 600 acres with woods, a sandy beach surrounding it with some sandy inland areas and other areas that are rocky. It has a pretty good mix of terrain and skill levels. Have to be careful taking novices though since a seemingly harmless trail can dead end into a brutal rocky hill climb.
The main thing is ALWAY look at this Army Corps link that shows the lake level before you go.
Keystone Lake LevelIf the lake is more then 3-4 feet over the 723ft conservation pool level the beach around the area starts shrinking removing some of the fun high speed areas.
If the lake level is over 735ft the road leading to the island will be under water.
If the lake level is below the conservation pool by 3-4ft make a special trip because that's when the area is at it's best.