Marmalade Dog, a con hosted by the West Michigan Gamers Guild (WMGG) and held on the Western Michigan University campus is the same weekend as Gary Con. I was able to attend both last year because they were different weekends.
Unfortunately, the date is set by the people in charge of the calendar at WMU and they have to take what they are given.
I intended to step up and make sure an OSR track happened this year, but I don’t want to put in all the work if I can’t follow it through to the end. I was getting ready to plan what games I might run, but figured I’d better verify the dates before I put in the work.
The cool thing about this con, if you sign up to run games by December 31, you get a t-shirt and free admission for each day that you run a game. So if you are nearby and won’t be at GaryCon, consider running a game at Marmalade Dog.
Find the closest game convention in your area and join in the fun. If you are unable to run a game for whatever reason, sign up to play. Even if you only participate for a day, you still show the convention organizers that there is interest, and it will happen again next year.
If you are looking for a list of game conventions, here are some sites that have lists.
Wikipedia also has a list of Gaming Conventions. Gamehole Con is missing from this list.
Board Game Geek has a good list that is also worldwide. Their list is a WIKI so it appears that you can easily edit to add to the list.
The site Upcoming Cons has a list that shows which cons are next, but it missing several cons on the other sites. Reading more about this site, it appears to be a tool for convention organizers to handle their registration, so it only has cons using its tools. This is a very narrow focus, so I can’t recommend it for finding a con in your area.
Lastly, if you can’t find anything local on these lists, do a google search for gaming conventions in your area. Once you find them, add them to the other lists so it is easier for others to find them. If you have an FLGS (Friendly Local Game Store), make sure that the local con is advertised there. If you are looking for people to play with in person, the FLGS and local cons are the way to go. The online sites for finding players only seem to work when you are closer to major metropolitan areas. Unless you want to drive an hour or more one way. Those sites are only as good as those who sign up. If there are none in your area, or none with an interest in your area of interest, you will be disappointed.