The H&L Lumber Company headed by Henry Lorimer and his daughter "Perry", receives a huge national defense order, and prepares to cut the dangerous Antler Valley tract. Eastern dude John Gordon applies for a lumberjack's job and Lorimer hires him. Soon, a series of accidents occur, topped by a forest fire of unknown origin, in which Lorimer is killed. Perry decides to carry on in her father's place, despite the objections of camp manager Barnes, who covets the company. The storehouse, where the dynamite needed to clear an avalanche is stored, explodes and Barnes blames Gordon. The latter has some cartridge cases used by the rifleman to explode the storehouse, and Barnes instructs his henchman Hodge Mason to get the evidence and kill Gordon. Perry overhears and attempts to stop them, but Barnes knocks her unconscious and puts her in the cab of a runaway train. Unable to keep Mason from reaching the plunger to set off an explosion to wreck the train, Gordon boards the speeding engine and races it over the danger spot ahead of the explosion. The engine and a few cars of lumber get through, and Perry is able to deliver the lumber order on schedule. Mason and Barnes are apprehended and Perry learns that Gordon is really John Gordon Hamilton, son of her late father's partner.