It is 1892 in Death Valley and the yields from the Borax ore are getting so small that refining it is a losing proposition. The only thing that will save the company is a new deposit of high grade Borax, and Skinner Bill Bragg has a pouch of it that he got from a dead prospector he buried on the road. Stag Roper knows the value of the strike could be worth millions, but he needs Bragg to find the prospector's claim so they can record it and become rich partners. While Roper has no intention of cutting Bragg in on the millions, he also has his eye on young Jean Johnson. Josie Johnson, Jean's mother, sees Roper as the scalawag he is, and that means trouble in Furnace Flat.

"'IT'S GOT THE KICK OF 20 MULES!'"