Just keep your eyes and ears open for all possibilities. Back when I was an osage cutting maniac, I was on high alert all the time, watching vacant lots with osage growing on them, any sign of clearing and I drove straight to them to ask the people clearing if I could have the osage, never was turned down.
Throw the words, bow making, osage and bodoc (Alabama pronunciation) out in crowds of people you don't know. Someone will say, "my uncles farm is covered up with that nasty stuff", or some other lead you can follow up on.
Just today I was shooting my flintlock with a group of guys, two I knew and four I didn't know. One of the guys who knew me said something about my osage bows. One of the guys who I had never met said"my farm is covered up with the stuff". Next question; mind if we cut some? "Cut all you want" says he.
That's the way it works, do your home work, ask around and you will have more wood available than you can cut