Toiletries and Medical Supplies: There is a small hospital on the island, as well as an ambulance and plane service for those in need of immediate care that is not available on the island. However, there is no pharmacy. Tylenol, Advil, etc. are readily available at many stores (and are quite expensive), but it is advisable to bring any medications you think you may need.
Luggage and bags:
Travel Light - Allow one for the many porters to move your luggage to your hotel. Tip generously!
Clothing/Shoes/Weather Gear: Comfort and style - enjoy yourself, but prepare yourself for all kinds of weather. July is capable of 40 degrees. Check the weather and add a jacket.
Toiletries and Medical Supplies: No worries, you can purchase everything you need on the Island. Be prepared for steep prices - they make their living with the markups. DON'T forget suncreen!
Photo Equipment: Bring your camera and enjoy the magic of the island!
Camping/Beach/Outdoor Gear: I like bringing my own bike...
Miscellaneous: For some strange reason, the sandals available on the Island are reasonably priced and novel...I've purchased some for myself and daughter recently.
Clothing/Shoes/Weather Gear: Even in the summer northern Michigan can be chilly and Mackinac Island is no exception. You will not need a sweater while biking around the island but if you eat anywhere outside, I recommend you have one.
Luggage and bags:
Don't bring tiny bags that are easily lost on the ferry ride over to the island. If needed bring bigger easily trackible suitcases. The last thing you want to start your vacation out with is buying a whole new wardrobe.
Clothing/Shoes/Weather Gear: Remember even though it may be 109 degrees where you live, in the summer, Mackinac Island's warmth peaks at about 88. Don't totally go for long sleeves but pack a variaty of clothing choices. *You don't want to need to buy clothes on the island because they get very expensive*
Miscellaneous: You may want to bring bikes over to the island, or rent them when you get there. Prices range from about $4-$10 depending on the quality of your bike
Clothing/Shoes/Weather Gear: One good tip for those going to the island is to take the temperature on the mainland, and then knock off ten degrees fahrenheit-- that's about how warm it'll be on the island. It really heats up around July, and some days are absolutely sweltering, but there's usually a nice breeze. So, my advice is-- bring layers. Definitely a sweatshirt. Pants are optional if you're coming in July or August.
Good walking shoes
Miscellaneous: It can get cool on the Island even in the highest heat of summer so don't be afraid to bring warm and cold weather clothes