Essential to the rapid increase in mine production was the further expansion of transportation facilities, including the competition between the Union Pacific and the Denver and Rio Grande Western railroads, which fostered the completion of spur lines and narrow-gauge district lines. Also essential was the development of mills and smelters needed to make the shipping of ores and concentrates a profitable enterprise. Custom mills and smelters virtually sprang up near many mines, beginning in the 1870s and continuing to the turn of the century. Most of these operations proved ephemeral, lasting only long enough to treat the grades of ore for which they were built. Of more importance was the construction of large smelting plants in the Salt Lake Valley. The erection of these facilities also commenced in the 1870s. In Murray, the Germania and the Hanauer plants functioned into the 1890s. They were purchased by the American Smelting and Refining Company (ASARCO) in 1899. ASARCO also purchased the Mingo smelter, built in Sandy in 1878. By 1902, ASARCO had begun operations treating lead-silver ores in its large plant in Murray.
The Midvale area became another key smelting region. In 1873 the Sheridan Hill smelter was built at West Jordan to treat ores from the Neptune Mine. The Galena smelter, constructed in 1873, treated ores from the Galena and Old Jordan mines at Bingham. It later became known as the Old Jordan Smelting Works. In 1899 the United States Mining Company--later the United States Smelting, Refining, and Mining Company (USSRMCO)--was organized, and in 1902 it completed its large smelter at Midvale. The ASARCO and USSRMCO plants, together with the International Smelting and Refining Company operation in Tooele, became giants on both a state and regional level in the consolidation of the smelting industry, .