As mentioned, the River Boat Discovery; also the Aviation Museum. (I always call the area "Salmon Bake Park".) The UAF Museum is worth the time; I especially liked the examples of some early Alaskan gunsmithing. If you're going through the effort to go to Prudhoe (which is like going through the effort to get dysentary), you may as well stop at the Hilltop north of town and have some pie....... Just leave some strawberry rhubarb for me. Stop at the Jim River by Pump Station 5 and catch a few grayling. Swing by Wiseman and get a candy bar at the Trading Post and visit with the colorful locals. Have fun!