The Prairie is set at the time of the Louisiana Purchase. Hoping to find their destiny in the new territory, the Bush Family heads southward in a covered wagon. Sharing the family's numerous dangers and hardships are Ellen Wade (Lenore Aubert), sole survivor of an Indian attack, and army mapmaker Paul Hover (Alan Baxter). Cousins Abiram (Russ Vincent) and Asa (Jack Mitchum) duke it out over Ellen's affections

Night club owner Russ Vincent hires boogie-woogie dancer Betty Hannon for a spot in a South American revue headed by Lita Baron (as Isabelita.) The latter is wary of Hannon's motives, but Vincent dismisses her feelings as jealousy.

Roy is an oil prospector. His efforts to get drilling rights on an old Spanish land grant are countered by gamblers from an off-shore gambling boat determined to control the land (and oil) themselves.