By the turn of the 20th century, Butch Cassidy, the Sundance Kid, Billy the Kid and virtually all of the West's legendary outlaws are either dead or in jail pending execution. Well, all, except train robber and escape artist extraordinaire, Harry Tracy. As the last survivor of the Wild Bunch, Tracy pulls off a series of profitable robberies before making his way west to Portland, Oregon, in search of Catherine Tuttle -- a judge's daughter who has captured his heart. But on the way, Tracy is betrayed, arrested, and imprisoned. However, no jail can hold him for long and after making his escape, Tracy becomes the target of the largest manhunt in the history of North America.
On his latest expedition, Dr. Rick Marshall is sucked into a space-time vortex alongside his research assistant and a redneck survivalist. In this alternate universe, the trio make friends with a primate named Chaka, their only ally in a world full of dinosaurs and other fantastic creatures.