The Hell Diggers.

Teddy Darman is the construction superintendent for the Continental Gold Dredging Company. But the farmers of the valley where the firm is doing its dredging are upset because it is ruining their land. Led by John Wade, the farmers form a fierce opposition. This doesn't bother Darman until he realizes that Dora (Lois Wilson), his sweetheart -- who is also Wade's daughter -- is siding with the farmers. This turns him around and the farmers mortgage their farms so that Darman can build a dredging machine that resoils the land.