Don't know if they still do it, but as of 10 years ago the forest service sold permits to take wood from national forest land. It had to be dead and on the ground. They were cheap, $25 or so. What I would do was go to where there'd been a logging operation the previous winter and take the treetops, branches, etc. Technically you were limited to 2 or 3 cords, but the ranger told me no one cares if you take more...just make sure you have the permit with you...fines were steep for taking it without a permit.
It's been quite a while since there's been any activity in the WMNF within a reasonable driving distance so I haven't bothered since the 00s, plus now many/most loggers chip all the slash.
Once upon a time there was a similar program for state forests.