You're right about firearms discharge laws in metro fringe communities in the Twin Cities. (It does foul-up metro goose hunting.) However, I don't think the state has any laws that control firearms discharge. They leave that kind of control up to the cities and townships.
But, what I was referring to was zoning laws by local units of gov't that are in conflict with state laws. For example, Minnesota regulates the location of group homes, half-way houses, mobile homes, etc. The local units of gov't (the city you live in) can't make laws that are more restrictive than the state's with respect to certain regulated uses.
So, carrying this principle forward leads me to believe that if the state of North Dakota has trespass laws related to hunting activities, the counties, cities, and towns can't pass laws in conflict. That, of course, doesn't mean that a city can't ban hunting inside the city limits. They can certainly do that. But, that is different than the trespass laws.