Stan Bradford and his ranch hands, Whopper and Smokey, are driving a herd of horses to sell to Jeff Corbin in Valley City. Jeff needs the horses to complete wiring the telephone lines in the valley, but when Stan presents Jeff's check for the livestock at the town bank, he learns that there are insufficient funds in the account. Under the pretense of helping his "friend" Jeff, Cobb Wayne pays Stan cash for the horses and promises to turn them over to Jeff. Unknown to Stan, Wayne will be awarded the telephone contract if Jeff misses his deadline, and to assure that Jeff will be delayed, Wayne intends to keep the horses. After Stan collects payment for the horses, Jeff's sister Mary arrives on the local stage, bearing bonds to pay her brother's debt. To prevent Mary from cashing the bonds, Wayne sends his men to bushwack her. As Stan, Whopper and Smokey ride back to their camp, they notice Wayne's men trailing Mary and ride to her rescue. Stan then drives Mary to her brother's camp, arriving just as an argument erupts between Jeff and his men over his inablility to pay their wages. Feeling guilty for having sold the horses, Stan offers to lend Jeff the payroll, using Mary's bonds as collateral. When Stan tries to cash the bonds, however, the banker suspects that they are stolen and has him arrested. Stan sends Smokey and Whopper to bring Mary to corroborate her story, and when she appears, the sheriff jails her for stealing the bonds and frees Stan. Stan, Whopper and Smokey return to Jeff's camp, arriving just after Jeff has been shot by one of Wayne's men. They take the wounded Jeff to town, where they learn that Mary's lawyer has substantiated her ownership of the bonds and she has been released from jail. Mary refuses to repay Stan's loan, however, unless he agrees to compete building the phone lines. To meet the deadline, Stan must string the lines through Placer Canyon, and as he and the crew drive toward the canyon, they are attacked by Wayne's men. After driving off their attackers with dynamite, Stan and the others set up camp. As a diversion, Wayne dynamites the canyon walls, and when Stan, Whopper and Smokey go to investigate, Wayne and his men knock Pete, the camp foreman, unconscious and drive the crew from the camp. With the canyon walls destroyed, Stan decides to string the wires along trees across the ridge and returns to camp. There, Pete tells them what has happened, and Stan sends Smokey to round up their ranch hands for reinforcements, while he, Mary, Whopper and Pete string the wire. As the deadline approaches, Wayne and his gang fire on the crew, wounding Pete. When Smokey and his men ride to the rescue, Stan strings the last wire just in time to beat the deadline.