Wade Benson, road construction boss anxious to help the East-West Company obtain the government mail franchise, is aided by his pal, Cyril Addlebert "Si" Dugan. Through the treachery of a rival line, Wade is forced to kill gunman Smoke Dawson. Bob Courtney, representing eastern interests, witnesses the shooting, as does Kay Randolph, and the two, being unaware of the plot against Wade, turn against him. Meanwhile, the rival company is actively frustrating the East-West plans and forces Wade's stage-line road crew to quit work. Following a fight, Bob makes up his mind to help Wade and talks the men into rushing the last bridge through to completion in time for the government's test run.