Are you talking about riding an ORV or a snowmobile on them? Some of the "bike trails" North of Baldwin (like the Manistee loop) serve dual purpose for sleds/bikes/quads/cars - these trails remain OPEN for quads and bikes during the winter and you only need a valid ORV to ride THEM on IT. If you do though, be careful not to continue on sled trails that are not marked ORV too! TICKET TIME and alot of sledders are majorly protective of their groomed surfaces - u dont wanna a bunch of them pushing you off into the deep stuff! I was recently on a roadway on my KX500 (street legal) and I had a sledder jump in front of me - I stopped - he started in on me about wrecking HIS trail :) I politely said "this is a ROAD and I am LEGAL - I sorry but we have to share" I then reminded him of how DUMB it was to step in front of a MOVING vehicle with studded tires that has a tendency to "wheelie" over stumps and other stuff that gets in the way.... He appologized, but the contreversy doesnt ALWAYS end so friendly like :(
On the other hand, if your question is - can you ride a SLED on any area's with only an ORV sticker the answer is no - gotta be registered and have a sled "trail permit" to be legal anywhere in the state except on private land (lakes may be different).
Hope this helps.
Woodsy
Also, if you ride those trails that serve dual purpose - watch out for SLEDS - they FLY those trails!!