Ore Hill History
The 48-foot wide Ore Hill vein was discovered by the landowner, Mr. True Merrill, in 1834. The ore deposit contained several sulfide minerals including pyrite (iron), galena (lead), and sphalerite (zinc). The stone foundations of the Merrill farm are located just northeast of the mine site, and site photos from approximately 1890 to 1910 show the Merrill barn in the background.
The ore deposit was operated intermittently by various operators from 1834 to approximately 1915 for lead, copper, zinc, and silver. A 1984 thesis reports estimates of mine production of between 50,000 and 100,000 tons.
Mr. Merrill sold the mineral rights to a Mr. H. Bradford in 1834, and the initial mining was for copper, but it failed to be economic. A second mining attempt by a Mr. Luke Brooks in 1838 also failed.
In 1840, a mineral survey of the mine and surrounding area found copper, iron, lead, zinc, and silver. That year, a Mr. Baldwin of Boston reopened the mine to produce copper, silver, and lead. A mill for separating the metallic minerals from the non-metal-bearing rock was built, along with “stamps” for crushing ore, and several residences were built nearby. The inclined shaft (the ore body dips to the east) was dug to a depth of 100 feet and a tunnel or “drift” 150 feet long was mined out. This operation also failed to be profitable.
In 1864, a Captain James Edgar built a new adit (a horizontal tunnel) and dug 100 feet into the hillside; he shipped 100 tons of ore to England, but it proved uneconomic. In 1869, Captain Edgar returned, this time mining for zinc. The shaft was deepened to 175 feet. To reduce shipping costs, the ore was “roasted” on site (most of the sulfur in the ore was burned off) and the ore was sent to Pennsylvania where the zinc was extracted. Again, the mine was not profitable and was closed.
The major period of mining at the site started in 1889 when the mine was reopened by the Warren Zinc Company and the inclined shaft was deepened to 180 feet. Despite a devastating fire in 1891, the company continued operations until 1893, when financial difficulties forced the mine to close. As many as 35 men were employed at the mine at one time.
In 1900, the Warren Separating Company reopened the mine. Fire struck again in 1905, destroying $40,000 of mine property. The owners rebuilt, importing new equipment, including a one-of-a-kind smelter from Belgium that took two years to build. The shaft was deepened to over 400 feet and considerable lateral work (tunneling or “drifting”) was done underground. The mine closed again in 1907 due to metallurgical difficulties.
The mine was reopened by the Warren Separating Company in 1914, and the shaft was deepened to 650'. A new technique for smelting was tried, but failed, so within a year the mine was closed again.
In 1927, the mine was pumped out and examined, but not reopened. In 1934, the mine was sold and much of the machinery on site was salvaged for scrap iron; newspaper reports indicate that the smelter was sold and shipped to Pennsylvania in the 1935.
When mining operations ended and the mine was abandoned in 1915, several piles of tailings and a pile of waste rock were left on site. A small drainage with poor water quality ran through the site and impacted water quality and aquatic species downstream in Ore Hill brook.
In 1937, the US Government acquired approximately ½ of the mine site to be part of the White Mountain National Forest.
The site was investigated by the Bureau of Mines during World War II for additional mining potential, and a report was published in 1948. Some mica was mined from the site in 1944, presumably from a small pit located northeast of the existing mine workings.
In 1962, the Forest Service planted red pine on the site, but few of the trees survived.
In 1979, the National Park Service acquired the non-federal portion of the site for the Appalachian Trail corridor, consolidating federal ownership. At around this time, the Appalachian Trail, which had traversed the unsightly mine property, was rerouted several hundred feet to the west of the mine site.
In the early 1980s, the mineral deposit was evaluated by a Canadian mining concern, but they did not reopen operations.
In 1984, the Forest Service, in coordination with the National Park Service which had acquired a portion of the site for the Appalachian Trail corridor, recontoured the tailings piles, capped the area with a thin layer of limestone and several inches of topsoil, and seeded the area. In 1988, additional work was done as some on-site surface water flow was diverted, and channels were lined with limestone. these actions improved the visual quality of the area and downstream water quality reportedly improved.
By 2000, when the Forest Service conducted a CERCLA Preliminary Assessment, several acidic seeps had appeared on site, the grassed soil cap on the tailings area was failing, and surface water at and below the site exceeded background and state water quality criteria for several dissolved metals by as much as two to three orders of magnitude.