Rangers help children complete the junior ranger program. NPS/Andrew Kuhn. The facilities management division maintains buildings throughout the park. NPS/Andrew Kuhn. Interpretation and Visitor Services. The interpretation and visitor services division manages fee collection; the visitor center, campground, and the park's volunteer program; and signs, exhibits, social media, and websites. Park rangers in this division also present guided walks, talks, hikes, evening programs, educational activities, and other special programs.