board of directors of the Dauphin and Susquehanna Coal Company in his 1840 reports "on the Coal Lands, Mines and Improvements" of that company, "the Swatara furnace, of Messrs. Guilford & Eckert" was "used with the hot blast" and produced "about twelve hundred tons of iron annually." The ore was "partly brown haematite from Chestnut Hill near Columbia, brought seventy miles, and partly from near Lebanon, about thirty-two miles." Production at the furnace ceased in 1853, ending both the partnership between Guilford and Eckert and roughly two decades of furnace operation. Listing on the National Register of Historic Places PHMC historic preservation specialist Diane Reed was the individual who prepared the National Register of Historic Places Registration Form for this district; she submitted it to the National Park Service of the United States Department of the Interior on March 21, 1991. The Swatara Furnace Historic District was then officially added to the National Register of Historic Places in July 1992. At the time the register listing was announced, newspapers also reported that members of the Pine Grove Historical Society and Pennsylvania Game Commission were working together "to reopen the park and maintain the furnace" as part of regional preservation efforts to preserve the historic structures located along Mill Creek. Notable structures The four contributing buildings of the Swatara Furnace Historic District are located along both sides of Mill Creek, and include: the furnace (1830), stone dam breast (c. 1850), ironmaster's mansion (c. 1830, c. 1860, c. 1881, and c. 1969), barn (c. 1860), stone foreman's house (c. 1830), and stone worker's double house (c. 1830). The furnace, which was built in 1830 roughly 150 feet south of Mill Creek, was constructed of limestone, and measures 29 feet, 7 inches, wide, 29 feet, 8 inches, deep, and 22 feet high. The original section of the ironmaster's mansion, which was built circa 1830 (around the same time as the furnace), was a 2-1/2 story stone structure which was "two bays wide … with six over six windows." The home's 3-1/2 story eastern section, which was subsequently added circa 1860, was "three bays wide, and four bays deep, forming an ell … with six over six windows and with shutters." A frame construction which added 2-1/2 stories to the home's north side was likely built at roughly the same time (c. 1860), according to PHMC historic preservation specialist Diane Reed. The stone dam