Ken Morley, driving a herd of cattle to the Charles Mortimer ranch, saves the life of Mortimer's daughter Mary when her horse is frightened by a mountain lion. Mortimer is at odds with neighboring rancher Marve Slater who insists that his cattle have a right to graze on Mortimer's lush grass range. Slater builds a dam at the headwaters of the river flowing through Mortimer's property hoping to force a deal. Ken finds the dam and hurries to Slater's place for a showdown. Slater's henchmen, after Ken whips up on Slater, imprison him in a bunkhouse directly in the path of a dam which threatens to burst because of a terrific mountain rainstorm. The dam bursts and the pent-up waters rush into the canyon below. Ken is tied up in the bunkhouse directly in the path of the oncoming torrent. Looks like a job for his horse Tarzan if Ken is to escape and put an end to Slater's dirty work.
—Les Adams <longhorn1939@suddenlink.net>