Not long after the Civil War, Texas cattle ranchers realize they have a problem--the Union Pacific railroad is bypassing their state and make it near impossible to get their cattle to market. Many ranchers are being forced to sell their land, and crooked state treasure Marvin Fletcher buys up the land at pennies on the dollar. However, Laguna del Sol Ranch owner Taisie Lockhart and her ranch hands are holding out. Cowboy Dan McMasters returns to the ranch and tries to rekindle his romance with Taisie, but she rejects him because he fought for the North during the war. But what she doesn't know is that Dan is on an undercover mission from the President to investigate Fletcher, and in order to do that he has to pretend to be sympathetic to Fletcher and goes to work for him, angering Taisie even more. Complications ensue.

Summoned to Shadow Ranch by his friend Ranny Williams, Sim Baldwin arrives to find Ranny has been ambushed and murdered. Sim learns ranch owner Ruth Cameron is under pressure to sell out to Dan Blake, as the dam on the ranch controls the town's water supply. Vowing to avenge his old friend's death, Sim takes up Ruth's fight and incurs Blake's hostility.

The plot revolves around a rivalry between sand-hog "Hard Rock" Harrigan (O'Brien) and his foreman Black Jack Riley. At the center of their conflict is their mutual affection for heroine "Andy" Anderson (Irene Hervey). But when the chips are down and Riley is trapped in a tunnel cave-in, it is Harrigan who comes to the rescue.

Kincade shoots Baird and takes the map to his gold mine. Sutherland finds the dying Baird who tells him the mine's location. Kincade, having lost the map, now goes after the gold Sutherland has taken out of the mine.

When Shag Smith kills Jim's brother Bob, Jim and Thunder quit the rangers so they can cross the border and join Smith's gang. Jim's plan is to get the gang to cross back over the border where the rangers will be waiting.

A stock market broker plans to liven up his boring life by taking up piracy on the high seas.