From 1910 to 1955, the mines at Reliance produced coal for the Union Pacific Railroad and were staffed by people hired from a variety of countries. During World War II, too few mine workers were available to extract the coal, so people were brought in from Oklahoma and Arkansas and housed in railroad cars. Even then, labor remained short, and women entered the coal industry workforce. Although women had long been considered bad luck underground and that superstition faded slowly, one of the first places they found work was in the Reliance tipple, where they worked alongside men in black dust, sorting coal throughout the war years at the picking tables inside the tipple amid the deafening noise of the shaking screens.