Australian sheep-man Morgan Lane comes to Montana looking for government-owned grazing land, and encamps his sheep at the boundary line (where the bad grazing ends and the good grazing begins) set up by the cattle barons to keep the sheep from nubbing away at the good grass. He goes to town, posing as a merchant, explains his Australian accent, and learns that Maria Singleton, owner of a large ranch, and Rodney Ackroyd (who never explains where he got his name), another ranch owner and Miss Singleton's fiancée, are the leaders of the cattlemen against the sheep-men. Romance tugs at Morgan and Miss Singleton, who quickly decides that Morgan has a much better name than Rodney (and other attributes) but the cattle-vs.-sheep feud keeps them apart. Until they meet in the street for a showdown gunfight following a disastrous clash between the cattle and sheep factions.

A stranger in a Western cattle-town behaves with remarkable self-assurance, establishing himself as a man to be reckoned with. The reason appears with his stock: a herd of sheep, which he intends to graze on the range. The horrified inhabitants decide to run him out at all costs.