Here in Ontario a crossbow is not considered a firearm, for intents of purchase and possession. Once you decide to hunt with it it does become recognized as a firearm by the MNR and must be treated accordingly, following the same laws for transport and storage.
I have met three game wardens in the past 3 days, each hunts with a crossbow in his downtime.

Thats another thing,even on a atv the bow/gun/crossbow have to be fully incased,you cant even wrap it intowel.
I wish Mn was more like ND when it came to transporting bows.