Confederate raiders disrupt laying the telegraph, but a brother helps the company succeed.
Vance Shaw (Randolph Scott) flees a posse, and his horse goes lame; but he holds up injured Edward Creighton (Dean Jagger). They hide, and Shaw walks with him to the stage depot. Then Shaw takes his horse. Edward is the telegraph engineer and hires men, persuading Shaw to stay as scout. Surveyor Richard Blake (Robert Young) reports from the east and flirts with Edward's sister Sue Creighton (Virginia Gilmore). Richard is given a bronco to ride and tames him. Richard finds Shaw with Sue. On July 4th 1861 Edward reads a message from Lincoln, and they set out to erect poles. Sue says goodbye to Edward, Shaw, and Richard. At night Shaw rides back to see Sue and finds Richard there. Cattle are stolen, and a man wounded by Indians dies. Shaw does not suspect Indians and finds Jack Slade (Barton MacLane) and four men disguised as Indians. Jack says they are Confederate raiders and won't give the cattle back. Shaw tells Edward it was 200 Dakotas.
Sue arrives as telegraph operator. Edward tells her to go and assigns Shaw to put her on the stage. Scared cook Herman (Slim Summerville) is stopped from leaving, and Shaw says goodbye to Sue. Richard and Shaw see Indians. Homer (Chill Wills) suggests Richard warn the camp by wire. Shaw lets the drunk Indian leader search for liquor, but in a fight Richard shoots the Indian, causing Shaw to sock Richard. Indians raid the camp. Doc Murdoch (John Carradine) finds an Indian is white, but he dies. Edward asks Shaw about the Indians and makes him foreman. Edward, Shaw, and Richard find Jack with their horses. Edward pays him $5,000 and warns him. Captain Harlow tells Edward to stop the line because of the Sioux. Edward negotiates with Chief Spotted Horse as Shaw translates. Edward has Richard shock the Indians with wire to show them it is bad for them, and the chief makes peace. Edward offers extra pay when they get to Salt Lake City.
Shaw is summoned to help Jack and is captured. Jack plans to attack the camp. Shaw uses fire to free his hands. Jack and his men start a fire around the camp, and wagons burn. Doc treats Shaw's burns. Edward asks Shaw for the truth and tells him to get out. Shaw tells Richard that Jack is his brother. Shaw finds Jack in a barbershop and is shot. Shaw kills three men before he is killed by Jack. Richard and Jack shoot it out; Richard is wounded, and Jack is killed. In the final scene Edward, Sue, and Richard remember Shaw after the line has been completed.
Fritz Lang directed this colorful western that shows
outlaws using war as an excuse to exploit Indians and steal from
the company; but this folly proves self-destructive in opposing
the march of progress.