the black hills national forest has some kind of special regulations where you can ride wherever in the forest, I think it's because the whole place is already totally crisscrossed with trails.

 

Last summer while I was in the BH I stopped and asked for a forest service map, they informed me that riding on the old marked logging roads was the only riding allowed in the National Forest. I don't think that blazing a trail is allowed.

 

I am also from grand forks. Frostydog isn't kidding though, the trail system by Wallhalla in the pembina river valley is amazing. Been going there for longer than i can remember, goin up this weekend actually! Also there is a dune and trail system by Wahpeton i am told....