The 1892 Wyoming conflict between established cattlemen and immigrant farmers was the Johnson County War.
The dispute grew from range-control practices in northern Wyoming. Large ranchers accused smaller settlers of cattle theft and sometimes used private detectives to enforce their claims. Many smaller ranchers argued that the cattle barons were using political influence and restrictive stock associations to control open range access.
In April 1892, an armed group recruited by prominent cattle interests entered Johnson County. They attacked suspected rustlers and besieged Nate Champion at his cabin near Buffalo. The Wyoming governor eventually called in federal troops, who escorted the invaders away and prevented a larger battle.
The conflict is often confused with the Lincoln County War in New Mexico, which involved Billy the Kid. The Johnson County War later influenced Western fiction and films, but the real event centered on land, livestock, law enforcement, and class tensions.