You will have to advertise in the small newspapers, contact farm bureaus, contact the chamber of commerces, taxidermy studios, locker plants etc. for information. Real estate brokers in that country often are ranch owners, leasing agents, or have listings on property that is in transition.
Buying can now be a problem, unless its really in the sticks or nearly unaccesable.Around Llano, some of that stuff is 3k-4k per acre, if you spring for 500+ acres.
Be in a hurrry, reasonable places go fast, early in the year.
Good luck on your search!