The loop through the Badlands takes you through Wall, SD, famous for nothing but Wall Drugs. The Buffalo Gap National Grassland is nearby, so I guess that's why the Forest Service selected Wall for the only Visitor Center it has for all 20 of the National Grasslands in the country.
Forest Service? I would have figured Bureau of Land Management... Apparently Department of Agriculture trumps Department of the Interior for prairies. (Of the 20 they manage, we've been through 5 of them--4 this summer: Little Missouri in North Dakota, Thunder Basin in Wyoming, Buffalo Gap in South Dakota, and Oglala in Nebraska. We were at Black Kettle in Oklahoma in 2011.) They manage the remnants of prairies in the country, places where the buffalo roamed and the prairie dogs still dig holes.
They have everything most national park visitor centers have: videos, exhibits, Ranger-led programs and a park store. (They even get good reviews on TripAdvisor.) Everything, that is, except Passport Stamps. The Ranger told us that "someone thought they needed it more than we do." They did give George a sticker!