- Fort-to-Fort 5-Mile Challenge -- The inaugural race occurred just this year. I think it's planned for the second Saturday in May, which is roughly when the island opens its season. The race starts inside Fort Mackinac, one of the island top attractions and winds through the interior of the island circling a second, smaller fort, Fort Holmes, then back to the start. You start from inside the fort to a musket salute (or maybe a cannon) then the route runs along beautiful wooded paved streets. It is very hilly. Not much flat at all, you are either climbing or descending pretty much the whole time.
This is a good time to be on the island. All the shops and restaurants are just opening for the season and it is relatively uncrowded. Key word: relatively. But be advised, it is not summer, just barely spring, and you are in the north woods. You could be facing quite cold temps. Check the weather ahead of time and bring the right gear. Early in the season also means probably it's your best shot at a reasonably priced room on the Island. - The Lilac 10k -- This is scheduled shortly after Memorial Day during the Lilac festival. (There are lots of Lilac bushes on the Island.) This race starts at the west end of "town" and heads east on a flat stretch on the main road then turns inland climbing a very steep road to the highest point on the island. The steepness should not be understated. The first quarter mile after you make the turn has most people walking. It continues to be uphill, though less steep for another mile or so. When you reach the water station you know you are at the top. Your reward for making it up is a long lovely downhill stretch, bisecting the island N/S such that you come out to the shores of Lake Huron almost directly across the island from where you started, you are now about half way. From there it's a flat half-circumnavigation counterclockwise on the shore road to the finish, about 500 yards from starting line.
The race itself is most notable for the uphill struggle and downhill reward. Barring strange weather patterns, this is usually in the heart of spring and the Island will be at its most lovely. The flowers on Mackinac Island are legendary. Weather should be good, but note: tourist season is in full swing at this point. Rooms will be dear, especially if you don't plan ahead.
- The Eight Mile Run -- This race is always the Saturday after Labor Day. It is an eight-mile circumnavigation of the Island along the shore road. You will run the entire length of M-185, clockwise, with Lake Huron on your left the whole time. You start at Mission Point, the big resort just east of town and run the circle from there. Simple. You'll pass through town, have terrific views of the Mackinac Bridge as you turn to run up the west side. Best of all, it is blissfully flat for the entire distance (well, there may be a brief undulation here or there but nothing to concern yourself with).
I love this race and I run it every year. I think this upcoming one may be my 10th. To me, it is about the perfect distance. Once you are comfortable with a 10k (6.2 miles) your next step up in distance is a Half Marathon (13.1 miles). I have never gotten to the point where a Half is not a struggle, and I've done quite a number of them. Usually around mile 9 or 10 I'm thinking, "this race is too long", and it becomes a question of pain endurance rather than fitness. This eight-miler is just about the perfect distance for me. I can really put everything I have into it without it become a question of survival.
Anyway, your weather issue here is potential heat. Rare, but it does happen. Usually if it doesn't rain, it's perfect. However, despite the fact that it's after Labor Day, rooms are still going to be dear -- plan ahead. If you like college football this is a good one, because after the race, everybody congregates in the bars to watch the games. - The Great Turtle Half Marathon and 5.7 Miler -- This is the last race of the season, always the Saturday before Halloween. It's also the only one with a shorter option. The Half starts at Mission Point and runs a couple of miles counterclockwise on the shore road before turning up a trail towards the interior of the island. Much of this race is on dirt -- either trails or dirt roads (there is a web of hiking/biking trails that criss-crosses the Island). The interior is hilly but I don't recall it being as hilly as the route of the Fort to Fort; that may be poor memory though. This being fall, the leaves are turning and the woods are bug free. Just a great trail run, if nothing else. The route provides you with stunning views from high above the town and harbor.
I have never done the 5.7 but it looks like you go from Mission Point straight up into the interior and barrel along a trail the runs along the east bluff, then plunge back down to the shore road for the last couple of miles.
This late in the season, as you would expect, the risk is cold weather, although that is somewhat mitigated by the mid-day starting time. You might think this late it would be easy to get a room, but Mackinac is a minor destination for Halloween parties also, so rooms will be high this weekend. That said, feel free to bring your costume and join the other dressed-up revelers is you have any energy left in the evening.
This is literally the last weekend the island is "open". The next day shops are closing up (you can find some good sales) and seasonal help is bugging out. Winter is coming.
If you're a runner should certainly try one of these races. They offer something for everyone and you get to be on Mackinac Island for a while which is the best reason.