Small correction . . .
The DNR is a State Department.
The NFS is Federal.
Both have their own definition of "Forest Road" which differ from each other - makes it a bit confusing.
4wd on State land other than a designated scramble area or an ORV ROUTE (NOT trail) is illegal.
4WD on Federal 'two-tracks' is OK -maybe.
It depends on if it's a Forest Road, or considered a 'user created' track.
NOT easy to find out, either.
Spinning your wheels and throwing dirt, sand, or mud is considered "Creating an erosive condition" be the DNR and is ticket-able.
County unimproved and seasonal roads can be a lot of fun. You're always legal to travel these, BUT you might have to "create an erosive condition" to navigate them successfully.
It all gets quite complicated.
STAY ON THE TRAIL!
You have to know who's land it is before you know which laws have jurisdiction.
Even unintentional illegal wheeling gives us all a black eye.
PM me if you want an in-depth conversation about it all.
Chair, GLFWDA Land Use Committee
VP, Two Trackers 4WD Club
Delegate, Michigan Motorized Recreation Council
Delegate, United Four Wheel Drive Associations
"quis custodiet ipsos custodes?" (Who will guard the guards themselves?)