Stop by a Black Hills visitor center and grab a map. There are hundreds of miles trails in the mountains, not to mention some incredible road touring with amazing views.
They publish road maps also for different skill levels on the road rides. For off road riding, you need to grab a sticker from the visitor center, and they're $25... I think cheaper for single day use. It's worthwhile though. The Black Hills has some of the best maintained motorcycle single-track that I've ridden - and I've lived all over the world.