Virginia, 1803. After the United States of America acquires the inmense Louisiana territory from France, a great expedition, led by William Lewis and Meriwether Clark, is sent to survey the new lands and go where no white man has gone before.

Fred MacMurrayas Cpt. Meriwether Lewis
Charlton Hestonas Lt. William Clark
Donna Reedas Sacajawea
Barbara Haleas Julia Hancock
William Demarestas Sgt. Gass
Alan Reedas Charbonneau
Eduardo Noriegaas Chief Cameahwait
Larry Pennellas Wild Eagle
Herbert Heyesas President Thomas Jefferson
Lester Matthewsas Mr. Hancock
Daniel L. Fapp