[15] It was built and operated by Robert Thornburg and John Arthur, in the interest of George Stevenson, who already owned Laurel Forge downstream on Mountain Creek.

[4] The Pine Grove Furnace facilities were identified as "Pine Grove Iron-Works" by 1782 ("Mr. Eger's [sic] iron-works" in 1783),[5] and in addition to water raceways and charcoal hearths (traces of which are still visible), support facilities were built near the works, e.g., the 1829 L-shaped iron master mansion [6] (named "office" in 1872).

[4] The 1870 South Mountain RR, with offices at Pine Grove, connected the furnace to limestone pits and three operating ore mines.

[11] The charcoal-fired furnace was deactivated in 1874,[8] and the engine house(s) continued pumping the ore pit (now Fuller Lake) to keep reduced water levels.

[17] A rail extension to the Wild Cat pits,[15]: 12  2.5 miles west of Pine Grove, was considered in 1880 but not completed.