Significant production of gold-rich pyrite ores in the Radersburg District of the Elkhorn Mountains during the 1870s led to construction of the Toston Smelter in 1885. The Toston Smelter Company, incorporated in August of that year and organized by Duncan T. Hunter, Everard Heneage, Frederick A.C. Amcotts, William K. Henson, and William L. Austin, was instrumental in the project, with metallurgist and company president Austin almost certainly the driving force. Austin and Toston Smelting built a pilot plant on the banks of the Missouri River one-half mile upstream, and after its success in the fall of 1885, Austin designed and built a full-sized smelter using the new pyrite process. The plant ran for less than two months before temporarily closing, and although the facility was remodeled and expanded, it still was not operating by late May 1887. The pyritic process, an early experimental type of smelting, had its first practical application in the United States at Toston, where nearby metallurgical materials, a transcontinental railroad, and abundant water made the site advantageous. Radersburg ore high in iron sulphide, brought from mines 12 miles away, was central to the method, which used heat from oxidation of sulphide in pyrites and therefore required little coal, coke, or charcoal, while needed coal and limestone were freighted only a few miles. The process drew interest to sulphide ores previously untreatable by other methods, but pyritic smelting at Toston ended only two years after it began when lessees converted the plant to a conventional smelter. Despite this difficult beginning, pyritic smelting later gained some wider use, including at a few copper smelters in Butte just after the turn of the century, and it was adopted and perfected by Robert Sticht, who took the technique to Tasmania, where it reduced Mount Lyell ores for more than 20 years. In August 1887, the Helena Mining and Reduction Company took over the smelter under a 16-month lease and converted it into a conventional lead-silver smelter. This operation succeeded where the earlier one had not, employing up to 150 men at the smelter and in related jobs in and around Toston. Most ore came from Radersburg, though some came from Idaho's Coeur d'Alene region, while coal came from a mine 3 miles up Six Mile Creek and limestone for flux from mountains 2 miles away. After the lease expired in early 1889, Toston Smelting resumed control, but the plant then operated only intermittently until closing permanently at the end of 1891. Although total production records are unavailable, during its most productive period under Helena Mining and Reduction Company control, the smelter processed 100 tons of ore per day for an estimated total of 48,000 tons. Mining, smelting, and trade drove Toston's early growth, and many men who worked at the smelter remained to farm, work for the railroad, haul ore, or labor in nearby mines. Earthquakes and fires plagued the community and nearly ended it by 1935. The place where the smelter dumped slag into the river became a popular swimming and fishing hole, and many descendants of early residents remain. In 2009, the Montana Department of Environmental Quality completed reclamation of severe heavy metal contamination on the 9.4-acre privately owned smelter site with funding from a $700,000 grant from the Federal Office of Surface Mining Control, Reclamation and Enforcement. No traces of the old smelter remain today.