A series of 25 2-reel Western thrillers in which a cowgirl aids the cause of justice and humanity in the Old West, often aided by her fiancé and her rancher father. Each episode tells a complete story in itself.

Barbara, finding her automobile disabled, is forced to go to the Storms reception in a taxi. The chauffeur brings her to the wrong house, and she finds herself greeted by The Blind Mole, as "English Rose." The Blind Mole, a picturesque Central American character, takes her into his confidence regarding his plans for a revolution in Costa Blanca. Suddenly Arenzo, a rival revolutionist, arrives with his followers, and in the battle that follows The Blind Mole is killed. Arenzo also thinks that Barbara is "English Rose," and forces her to accompany him. The scenes that follow, telling in exciting manner how Wallace and a reporter succeed in unraveling the mystery of Barbara's disappearance and how that adventurous girl thwarts the schemes of the "gun runners," culminate in a spirited conflict aboard the schooner which was to bear the revolutionists' arms to Costa Blanca.

The first, and apparently only, surviving film produced by the Colorado Motion Picture Company, Pirates of the Plains is a quite well-made story about two brothers, one a champion rodeo rider, the other a horse thief.