Eagles nest in Oshweken SUCKS. Do not go there. It sucks so much that it's not safe in my opinion. Big square holes in landings, typically filled with old tires or concrete rubble. I have ridden almost every single track in Ontario and that place is at the bottom of my list. The owner does not look after the place. Nobody I ride with ever rides it, despite that it's 30 min away, we would rather drive 2 hours to go to another track.
Gopher dunes in courtland is amazing. It's a national track and is the roughest sand track in Canada when it gets chewed up, which I like to an extent. Deep sand riding is a bit frustrating until you figure out how to weight the bike and keep that throttle twisted. The trails there are pretty good as well! It's worth the drive.
Also, motopark in chatsworth. Awesome track, and a crap load of trails that are a bit more technical than the ones at gopher dunes. There is also camping with hookup there if you need it.