Captain George Curtis is sent from Washington, D.C. to improve conditions on an Indian reservation. After ousting a prejudiced government agent, George earns both the allegiance of the Indians and the hostility of neighboring cattlemen, who hope to appropriate the reservation through political corruption. George also falls in love with Elsie, the daughter of ex-Senator Brisbaine, a sworn enemy of the tribe. When the murder of a white rancher by an Indian incites an attack on the reservation, George marches his Gray Horse Troops into town to quell the violence. He then captures the perpetrator and assures the ranchers that the incident was isolated. Although they demand revenge on the entire tribe, George maintains the peace, and wins Elsie's love.