I'm not sure they will. They won't even do those jobs close to home, why would they travel some distance to do them? It's a different world from the time of the depression. Folks just aren't desperate now, with the social safety net available in most places.
I don't think you can legally COMPEL anyone, short of convicted prisoners to do any particular work at all.
What do you think both federal and contract wildland firefighters do? They can be gone months at a time, and know this when they sign on. The benefit that draws them, of course, is the overtime that they make while away from home. Or what about private contractors who are working in Iraq or Saudi Arabia-not exactly garden spots for your average westerner (not to mention the risk of getting your head cut off with a dull knife)?
Pay enough and they will come.