Free: Contests & Raffles.
Closing roads would definately help with spike recruitment. I think that this option is much more attractive than turning those units into permit only.
I remember in the late 70's going out in the evenings while my father was logging up there watching the enormous bulls and hundreds of cows.
Last year when I was wandering around 328 I came across a couple of brand new gates on roads that had signs on them that the RMEF was at least partially responsible for putting those in. I don't know if they've purchased land or not, I just saw the gates. (More, please!)