Muzzleloading Deer Seasons An individual hunting deer with a muzzleloading firearm during the muzzleloading deer season shall only possess or carry afield, or take a deer with a crossbow, muzzleloading rifle, muzzleloading shotgun, or black-powder pistol, loaded with black-powder or a commercially manufactured black-powder substitute. Exception: Zone 3 is open to all legal firearms, including the full counties of Oceana, Newaygo, Mecosta, Isabella, Midland, and Bay. Only certified hunters with a disability may use a crossbow or a modified bow during the muzzleloading season in the Upper Peninsula, except in the UP Core CWD Surveillance Area where crossbows may be used. See “Archery Deer Seasons” for possession and carry of firearms during the coinciding late archery deer season. https://www.michigan.gov/documents/dnr/hunting_and_trapping_digest_461177_7.pdf It's a little confusing at first. But certain counties are set aside for "all legal firearms".