The Leases of the P&BMC

Detail of a Survey of Location No. 4 for the Pittsburgh & Boston Copper Harbor Mining Co. (Image courtesy Detroit Public Library Burton Historical Collection)

This is the third in a series of posts providing an historical context for the Cliff Mine beginning with the creation of the State of Michigan and ending with the discovery of the Cliff vein.

The property of the newly formed company comprised three leases, each nine square miles in size, numbered 4, 5, and 6. Professor Forrest Shepherd of New Haven, was dispatched in 1845 to examine each and report to the company their condition. Shepherd reported Lease 4 to be, “the most valuable and interesting of all the locations on Lake Superior.” It encompassed the whole of Copper Harbor, including the village, the land agency, as well and the newly constructed Fort Wilkins, which housed military personnel believed necessary to defend miners from the native population. The lease property consisted of uneven land, some good opportunities for waterpower, “a good supply of pine and other timber” and nearly 40 mineral veins of dense, “calcareous [occurring in limestone] spar.”

Lease 6, located about 26 miles west of Copper Harbor, “commands the whole shore for about four miles; is watered by five small streams or rivulets; and [is] covered with heavy forest of pines, firs, hemlocks, oaks, maples, and cedars.” Shepherd’s description lacked detail as to the location’s mineral prospects, and mainly noted the presence of cultivable land in the south and good building stone along the shore. Seen as the least promising of the three, the company chose not to renew No. 6 in 1847, as by that time, what was being found at Lease 5 made it unnecessary to divide attention between three locations.

“As… not more than one-hundredth part of the tract has been properly explored,” Shepherd was unable to heap the same praise on Lease 5 as No. 4, but felt that copper could be worked, “economically and profitably.” Lying along the shore of Lake Superior at the mouth of the Eagle River, the lease extended southward where:

The sudden 250 foot fall to the west branch of the Eagle River at Lease 5. (Photo by S. Gohman)

“The land rises from the lake gradually for about two miles inland, where it obtains an elevation of five hundred feet or upwards, and then suddenly falls about two hundred and fifty feet to form the valley of Eagle River. A heavy forest of oak, maple, birch, hemlock, fir, cedar, white and yellow pine clothes this tract. About two thousand acres of this tract will be arable, and the whole fit either for tillage or pasturage.”

Using the mines of Cornwall as reference, Shepherd suggested this gradual rise and sudden drop would provide excellent drainage north and south for any future mining endeavors located there. Describing the geology, Shepherd noted the presence of alternating conglomerate and amygdaloidal trap, traversed by “numerous…broad veins of calcareous spar, yielding more or less of copper.” Three veins huddled in the center of the tract had so far been uncovered, the westernmost (named for Hays) and middle veins possessing native copper. It would be this middle vein that would soon garner the most attention, but not until the veins of Lease 4 had been thoroughly explored.

Further reading:

Forrest Shepherd, Geological Survey of the Mineral Lands of the Southern Shore of Lake Superior, Belonging to the Pittsburgh and Boston Copper Harbor Mining Company. (Pittsburgh: George Parkin, 1846).

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About Sean Gohman

Currently a PhD Degree seeking student in the Michigan Tech University's Industrial Heritage and Archaeology program.

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