When politician William Proctor (Harrison Greene) announces that a dam will be built on a site where many settlers have built homes, a retired major (Eddy Waller) who founded the settlement leads a backlash. Eventually, the fight comes to the attention of the Three Mesquiteers -- Stoney Brooke (John Wayne), Tucson Smith (Ray Corrigan) and Rusty Joslin (Raymond Hatton) -- who try to find a peaceful solution. However, they soon realize Proctor will resort to any trickery to get his way.