Another thing you may consider is using a plat map to find out who owns some land that looks promising. Once you find their name on the plat map, you can use whitepages.com to find their phone# and call them. It may be quicker and easier than trying to figure out who owns the land by where their farmhouse is located. My fam owns 1800+ acres in NE MO (just east of atlanta) and my great-aunt (who manages the land) lives south of there in Macon nowhere near our land so you would never know who owns it by just looking for farmhouses. Anyway, here is a link to where you can find a large number of plat maps for MO:

http://digital.library.umsystem.edu/...e-idx?c=platic

Hope this helps,
Sean