Pine Grove RV park right off I-80 between Lincoln and Omaha is a nice place to stay, been there twice. Lots of things within a short drive time from there. The SAC museum is one exit down to the east on 80, and south of that is a wildlife refuge with Bison and bears and wolves. Omaha has a really great zoo too that you need 2 days to see it all, and I highly recommend eating at King Kongs across the street from the zoo. There is also an old railroad terminal that is a museum, really nice place to visit to learn about that areas railroading during it's heyday.