The booklet we picked up at the Visitor's Center lists several tours (you can take on your own) and describes the length of each and what you can see on that tour.
#1 - Fort Mackinac, the view from the top. This is located on the hilltop and only available by walking. It takes ½ to 2 hours. The book lists the various things in the Fort. (This is a fee area.) We did find out that Ft. Mackinac's primary purpose was to protect the fur trade. From 1780 to about 1835 Mackinac Island was the principal shipping center for wild animal pelts destined for Eastern and European markets. Much of this market was controlled by John Jacob Astor.
#2 - Furs by Astor, Along Market Street - walking or bicycle, 1 hour. Many of the houses here were the original houses that existed when John Jacob Astor ran his fur trade on the Island.
#3 - Indians and Missions from Father Dablon to moral re-armament. Walking or bicycle, 1 to 1½ hours. This one again is pretty much in town and shows several of the buildings used by the early missionaries in their attempts to convert the native inhabitants of the Island.
#4 - Natural History Highlights. Walking or bicycle, 1 to 2½ hrs. This is a little longer trail but takes you past some of the beautiful limestone formations on the Island.
#5 - Down the middle, route of the British. Walking or bicycle, 1½ to 3½ hrs. This takes you right across the middle of the Island. It shows the various historical sites from the British invasion of the Island.
#6 - The town and people. Serving tourists for 150 years. Walking or bicycle, 1½ to 2½ hrs. This takes you through the heart of town and allows you to see all the quaint little shops that are there, as well as go past the Grand Hotel. There are any number of small shops, as well as restaurants. One of the things that you have to be sure and purchase is the fudge. There are several shops in town that feature their famous fudge and I have to attest to the fact that it is delicious. (Oops, there go the hips again! maybe I can work it off on the bike ride)
#7 - 'Round the shore. Bicycle, 1½ to 3 hours. This trail takes you around the perimeter of the Island which is 8.2 miles. This is the one that we opted to take because we felt it would give us the greatest overall picture of the Island. The ride was just lovely. Mostly level, but there were a few hilly spots. Along the way we were treated to local flora, as well as some of the limestone formations. It was really a nice ride, especially since you didn't have to worry about getting run over by passing cars. However, there were a few dodging maneuvers that we had to make since the horse-drawn carriages come the same way and they don't have porta-potties for horses. It was a little embarrasing at one point when a lady in her 70's riding a bike pulling a little trailer behind passed me. She was obviously a local resident who had traversed this road many times going back and forth from her house to town. However, I did catch up and pass her later on. (Whew! thought I was getting old or something).
I got the feeling as we rode along that even in the section of the Island that was not close to town that a lot of maintenance was done, since the brush had not overgrown everything.
Although we opted to just take the ferry over and back, there are any number of hotels and bed & breakfast lodgings that you can stay at, either overnight or for a couple of days. The B&B's are very picturesque and would give you more time to see everything.
We timed our ride so that we arrived at the dock just a little before time for the last ferry to leave to go back to Mackinaw City. Since it is not the official season yet, the last ferry left at 6 p.m. During the tourist season the last ferry will leave as late as 10:30 or 11 p.m. As we were boarding the ferry we struck up a conversation with a couple who had lived on the Island some 20 years ago. As I was asking her how one goes about moving their furniture on or off the Island she pointed out a large dray that they were pulling off the ferry. It looks like a large wooden skid with wheels. They pull it off the ferry with a small motorized fork-lift which never leaves the dock area. It is then picked up by a team of horses that is hitched up to the dray and taken to the residence where the furniture will be moved in.
As we sat back and got comfortable to enjoy the ride back, my sore muscles told me that I had had more exercise than I had in awhile. However, the beautiful memories and pictures that we had were more than worth it.

 

Good Luck! Have Fun! and Stay Safe!

Laura