Mine Hills Preserve in northwestern Roxbury, Connecticut, spans three hundred sixty acres and preserves the remains of a nineteenth-century iron mine, furnace complex, quarry areas, and workers’ settlement on Mine Hill. First known as Spruce Hill, the land saw unsuccessful mid-eighteenth-century efforts to mine gold, silver, and lead, leaving some surviving shafts. Its most important industrial period began after carbonated iron ore was identified there and development finally proceeded in 1865 under the Shepaug Spathic Iron and Steel Company. Iron operations ended in 1905, quarrying continued until 1935, and the site was listed on the National Register of Historic Places in 1979.