In 2019, Stephen Major and his "Extreme Expeditions Northwest Team" embark into the Colville National Forest to uncover Bigfoot signs, document strange happenings, and track down the illusive creature.

Young Indian brave White Bull captures and tames a wild stallion and names him Tonka. But when White Bull's cruel cousin claims Tonka for his own and mistreats the horse, White Bull sets him free. Tonka finally finds a home with Capt. Keogh and the 7th Calvary, and in 1876, rides into the Battle of Little Big Horn with General Armstrong Custer, becoming its only survivor.