The Porter family, Tom, Kevin, and Annie get sucked into a prehistoric alternative world while taking a family vacation. The Porters build a tree house, hook up with a few locals, Tasha - orphaned, an extra smart dinosaur, Stink - a monkey man, and Christa - another human who has lived in the Land of the Lost since she was a little girl. The Porters must deal with living with dinosaurs and avoiding the evil advanced Sleestaks.