First thing I would do is get a soil test kit and send it in. It is inexpensive and will tell you just about everything you will need to know about what the soil, and what it does or does not have. You can then add lime and fertilize as needed. Please note, that adding lime into the soil may take some time, add lime now and plant in the fall type of thing. The second thing I would do would be to get a list of native grasses/plants from your parks service and then try to find seedlings or seeds to spread out. Finally, I would then draw out a map of what you want to put into native vegetation and what you want to put into food plots. Because of timing you do not want to be moving plant around.
You will be surprised at how quickly it will start coming back with some good rain, lime, and fertilization. Areas with nothing now can have plants growing in a year.
