sterling hill mining museum grounds and zinc mine Sterling Hill Mining Museum grounds in Franklin NJ


Tour the Sterling Hill Mining Museum


Artwork and sculptures representing miner life are on display in Zobel Hall.



Sterling Hill Mining Museum: Trotter Tunnel

Before the Tunnel: 1730 to 1874

1881 photo of the mine

The west entrance of the Trotter Tunnel (near bottom of photo) along the east wall of the Noble pit, as it appeared circa 1881. Note people on crest of hill at left and on pit floor at lower left for scale. The photo was taken looking eastward from a vantage point on the west side of the Noble pit.

The Noble Mine, a name used to describe the southernmost workings at a rich zinc deposit shared by the famous Sterling Hill Mine to the north, had a complicated and litigious history. Prior to the “great consolidation” of 1897, the Sterling Hill deposit was divided into multiple lots, each controlled by different, and, in some cases, multiple parties. Unlike the adjoining lots to the north, the lot comprising the Noble Mine could be worked for both zinc and iron due to a greater-than-normal concentration of iron in franklinite, one of the principal zinc ore minerals in the deposit. From 1897 onward, control of the entire orebody was unified under the New Jersey Zinc Company, which continued its operations until 1986.

The mineral deposit was discovered as early as 1730 but misidentified as copper ore. This is likely due to the fact that some of the minerals within the deposit, such as zincite, bore a physical resemblance to certain copper ores. As a result, early prospectors were unable to smelt it. By the 1760's, William Alexander, who had assumed the title “Lord Stirling,” and after whom the tract of land was later named, acquired the property. He too was unable to smelt the ore. Following his death in 1783, the property came under the possession of Robert Ogden and his sons. A family of notable iron industrialists, they too were unsuccessful at mining the zinc or iron ore.

The entire tract remained wholly within the Ogden family until 1837, when the southern portion was sold to Robert Ogden’s son-in-law, Samuel Fowler, a renowned mineralogist of his day. Despite having exerted a substantial amount of effort, Fowler also met with failure while attempting to work the ore. Upon his death in 1844, the mine passed to his heirs. Samuel Fowler Jr. sold the mine in 1847 to the New Jersey Zinc and Copper Mining and Manufacturing Company, which held the property until selling it back to Fowler in 1853.

more recent photo of the trotter tunnel adit

The west entrance of the Trotter Tunnel as it appeared in 2011. This entrance is along the nearly vertical east wall of the Noble pit.

Samuel Fowler Jr. then divided interest in the mineral rights into distinct parts, separately for zinc and franklinite (iron). His interest in the zinc was sold to the National Paint Company. In 1859, the National Paint Company subleased the mine to the Consolidated Franklinite Company, which agreed to drive a tunnel “sufficiently large for all mining purposes.” This was the earliest proposal to dig a tunnel, but their plan never materialized, and the National Paint Company went bankrupt before 1861. On July 1, 1863, John S. Noble began mining zinc ore by permission from James L. Curtis, who had acquired the right to mine zinc on the property. Noble mined the ore via open pit methods. After a series of convoluted transactions, the title to the zinc eventually was transferred to Henry Aitkin, George W. Jewitt, and William C. Squier, who held onto it until 1896. It was then sold to the Passaic Zinc Company before that company was consolidated into the New Jersey Zinc Company the following year.

The title to the franklinite rights, meanwhile, was passed by Fowler to Samuel Brooks and Silas Stillwell in 1852. The Sussex Iron Company then obtained the title in 1853, but sold it back to Fowler and James L. Curtis in 1854. The following year it was conveyed to the Franklinite Steel Company, presided over by Curtis. In 1871 this company consolidated into the newly formed Franklinite Steel and Zinc Company. Curtis initially served as the Vice President but later assumed the role of with drill

Construction of the Trotter Tunnel: 1874 to 1876

On April 28, 1874, Charles W. Trotter signed a lease with the Franklinite Steel and Zinc Company, permitting him to mine 10,000 tons of zinc ore. Trotter was already occupied in the sale and manufacture of white oxide of zinc in Elizabethport, NJ, and wanted to better compete with the Passaic Zinc Company and the New Jersey Zinc Company, both of which, at the time, were mining zinc from the two northerly lots. On July 6 of the same year, Trotter's crew began driving a tunnel from the base of Sterling Hill with the intention of reaching the primary ore, zincite. The Franklinite Steel and Zinc Company appointed Daniel T. Mapes to serve as engineer and supervise Trotter's work. It was Mapes' recommendation that Trotter drive a tunnel or adit to strike the zinc ore horizontally rather than work from the existing open pit.

Claiming a thorough understanding of the shape and orientation of the orebody, the company officers asserted that Trotter only needed to tunnel a distance of 150 feet to reach the zinc ore. Perceived by Trotter to be a relatively short distance, he decided to excavate his tunnel by the cheapest means then possible, by hand. Hence, Trotter neglected to invest in expensive machinery such as pneumatic drills and a steam engine, which would have been warranted for a much longer excavation. Unfortunately for him, this decision ultimately proved detrimental. It was not until February 1876, 360 feet in, that he had struck any ore, a mass of low grade hemimorphite. Having shouldered the cost of excavation himself, and done so inefficiently, it proved to be a major setback both financially and timewise for Trotter. Had he realized the ore was so distant, he would not have used such primitive methods.

within the Trotter TunnelThe hemimorphite was 14 feet in width but of such terrible quality that the mass on average would be unprofitable to mine. In July 1874, a second vein was reached containing franklinite, 70 feet in width. Although it paid to mine this ore, the Franklinite Steel and Zinc Company encouraged -- but did not require -- Trotter to instead drive the tunnel even farther to reach the promised rich vein of zincite. After proceeding 25 more feet, a third vein of hemimorphite 16 feet thick was struck. Trotter continued a short distance past this vein before terminating his tunnel at a total length of 505 feet in October of 1876, without ever encountering zincite.

Because of the company’s erroneous assumption that ore would be reached at 150 feet, and the fact that no zincite was ever found, Trotter was able to renegotiate his contract in his favor and recoup some of the cost. Immediately afterwards, Trotter attempted to find a market for the franklinite. Trotter was unable to generate any buyers, even after distributing a circular to a number of iron manufacturers announcing the availability of his franklinite for iron production.

Trotter TunnelThe Period of Litigation:
1877 to 1897

Since Trotter failed to find a market for the franklinite, the Franklinite Steel and Zinc Company issued a lease to John Silsby in March 1877. Silsby was described by one of his acquaintances as “a man of large means amply sufficient to furnish all the necessary capital for working and developing the mines.” He was assisted by Henry Martin, who was said to have significant experience in the mining industry and relationships with iron manufacturers throughout Pennsylvania and elsewhere. Silsby, whose lease included no provision to acknowledge the lease of Trotter, was intent upon using Trotter’s tunnel. In addition, just thirty days prior to the issuance of Silsby’s lease, the Cambria Iron and Steel Company had made an agreement with Silsby to purchase 20,000 tons of ore a year. To make matters worse for Trotter, an individual by the name of Mr. Henderson had also agreed to purchase ore from Silsby, in the amount of 12,000 tons a year.

Light from within the trotter TunnelSeeing as Silsby already had a ready market for ore, even before the execution of his lease, the Franklinite Steel and Zinc Company conspired to assist him in his efforts to mine and sell ore, to share in his profits, and to prevent Trotter from interfering. Silsby was also able to sell his ore much cheaper than Trotter, as he did not have to offset the price against the cost of developing a tunnel to reach the ore.

A bitter and lengthy dispute between Silsby and Trotter followed, neither party willing to agree to a compromise in the shared use of the tunnel. Several court injunctions followed. With each court injunction, the weight shifted steadily in favor of Trotter’s rights to mine and use the tunnel. However, Silsby often took advantage of Trotter, and on more than one occasion made it all but impossible for Trotter’s crew to work. Silsby’s workers were found to be more productive as well, encouraging the company to disregard Trotter even more. Finally, by January 1878, a final court opinion determined that Silsby’s rights were secondary to Trotter’s. Trotter would have almost exclusive use of the tunnel. With Silsby's rights now subordinate to Trotter’s, he would have the right to mine iron and zinc ores only upon properly notifying Trotter, and only when it was not deemed necessary that Trotter have sole use.

Unfortunately, Trotter’s victory was brief. In April 1878, the Franklinite Steel and Zinc Company sold its rights to a third party intermediary, which then transferred them to the Manganese Iron Ore Company, presided over by none other than John Silsby. Bearing no legal obligation to recognize Trotter's lease under the new company, Silsby asserted complete control of the tunnel and went on to mine 45,000 tons of franklinite iron ore by 1879. He then purchased the remaining rights to the zinc title from the National Paint Company during its liquidation.

recent photo of the trotter adit

The partially reconstructed east entrance to the Trotter Tunnel, adjacent to Plant Street.

John Silsby’s reign did not last long. In 1881, Silsby published an elaborate prospectus to market his ore. However, he was no longer able to maintain a market for ore as he once had, and the Manganese Iron Ore Company went bankrupt. In 1887, the renowned Edward Cooper and Abram Hewitt acquired the company’s assets. They apparently did not accomplish much mining, and in 1896 they sold the mine to the Passaic Zinc Company. The following year, the Passaic Zinc Company was consolidated into the New Jersey Zinc Company.

The Modern Era Begins:
1897 to the Present

From 1897 onwards, the New Jersey Zinc Company worked the entire deposit at Sterling Hill as a single entity. During this lengthy period, a powder magazine was added from inside the tunnel and electric lighting was installed. In 1986, the Sterling Hill Mine was permanently abandoned and the entrance to Trotter’s Tunnel capped. Three years later, the entire mine site was acquired by Richard and Robert Hauck, who opened it to the public as the Sterling Hill Mining Museum.

The Sterling Hill Mining museum began offering tours of the historic Sterling Hill Mine in 1990. In mid-April of 2011, the museum began rehabilitating Trotter’s tunnel. Finally, on April 30, 2011, the museum hosted its first-ever private tour of the Noble Mine as part of their Super Dig event in cooperation with the Delaware Valley Earth Science Society and the North East Field Trip Alliance. Led by Iron Miners, a company dedicated to preserving mining history, visitors were afforded the first-ever public opportunity to tour Trotter’s historic tunnel. A subsequent tour followed on April 28, 2012, also led by Iron Miners. Today, the legacy of Charles W. Trotter lies largely forgotten, yet forever etched in the tunnel walls beneath Sterling Hill.

map of the trotter tunnel

Map showing the location of the Trotter Tunnel in relation to other parts of the mine workings.