This site has been self-guided every time I have visited. It has an old steam locomotive, a carpenter-Gothic-style church that has been moved in, and the old weather bureau building, which I believe was a former officer's quarters at the fort. The church is still used for weddings.
The premises house several historical buildings from different eras in the town's history, and it is a free historical attraction in Bismarck. Park nearby, come here and read the info plaques, and go have a cup of coffee at a nearby downtown cafe.