In Dakota territory in the 1870s, White Bull, a young Sioux, proves his manhood by catching and training a wild colt he names Tonka. When a cruel cousin claims the horse as the privilege of rank, White Bull lets Tonka go. The horse ends up in the hands of a captain in the US cavalry about the time that Sitting Bull gathers the tribes to confront the growing US presence, epitomized by the bigoted General Custer. All paths, including those of White Bull and Tonka, lead to the confluence of the Little and Big Horn rivers.

The deranged adventures of Gonzo journalist Hunter Thompson and his attorney Oscar Acosta, referred to in the movie as "Laslow". Thompson attempts to cover the Super Bowl and the 1972 Presidential election in his typical drug-crazed state, but it continually and comically sidetracked by his even more twisted friend Laslow. Allegedly based on actual events.