Pittsburgh and Boston Copper Harbor Mining Company Sites, Fort Wilkins State Park Copper Harbor, Keweenaw County, Michigan



Michigan Technological University's Industrial Archaeology program conducted six weeks of field survey and test excavations at Fort Wilkins State Park (20KE13), Copper Harbor, Keweenaw County, Michigan during June and July 2000. The fieldwork was part of a two-year cooperative agreement with the Michigan Historical Center to train undergraduate and graduate students in archaeological methodology on state lands. Students from MTU, Eastern Michigan University, George Mason University, and volunteers participated in the field school, directed by Drs. Patrick Martin and David Landon. Michael Madson and Elizabeth Norris, graduate students in the IA program, supervised undergraduate students in field survey and excavation methodology.


The Pittsburgh and Boston Copper Harbor Mining Company was one of the earliest copper mining concerns on the Keweenaw Peninsula. The company mined copper-bearing silicates at Copper Harbor between 1843 and 1847, until operations were transferred to the much more profitable Cliff location. The workings at Copper Harbor were sizable; at times the company employed up to 70 men. According to contemporary accounts the company employed, in addition to supervisors and contract miners, blacksmiths to produce and repair mining tools and coopers to make wooden barrels to transport ore to eastern markets. In addition, at least two contemporary authors suggested that the company construct a smelter to process some of the poorer ores on-site, considering the costs of shipping these ores to market. One source even mentions that the company had the necessary materials to construct such a furnace. Although the company proposed to build a smelter along the banks of nearby Fanny Hooe Creek, commanders of Fort Wilkins, a U.S. Army outpost adjacent to the mine operations, denied the request.


Students and faculty identified two areas during field survey to be the focus of test excavations. Upon further excavation, one area was determined to be the company's blacksmith shop. Tabular red sandstone and yellow firebricks represent a probable forge base. The diverse artifact assemblage at the blacksmith shop area included window glass, a pocket knife, iron scrap fragments, bar stock, and numerous mining tools including a complete miner's pick and drill steel bit, blacksmith's tongs, an iron file, a maul/sledgehammer, and the handle of a bucket typically used for lifting ore from the mine. Also present are blacksmithing by-products, including coal, charcoal, ash, limestone (for flux), and slag. A bladed reaming tool, possibly used to drill bung holes in wood barrels, hints that a cooperage was either included at the blacksmith shop location or in the vicinity. Building remains included an intact timber sill and substantial architectural nails and spikes. A charcoal pile nearby, 1 meter thick, represents fuel storage for the blacksmith's forge.


The second study area appears to be the remains of an incomplete or short-lived furnace or roaster for the processing of copper-bearing ores. Cultural materials, particularly an intact drill steel similar to the one identified in the blacksmith shop location, indicate the area was indeed part of a mining operation. Domestic artifacts included mid-nineteenth century, sprig painted polychromatic English whitewares. The sizable three-sided feature, approximately 1.5 x 3 meters, with walls constructed of tabular, rounded, and subangular basalt cobbles and tabular red sandstone chunks, has a floor of small, flat, and rounded cobbles, set on edge. Yellow firebricks and structural, tabular red sandstone fragments from the features deflation are present within and north of the feature. Artifacts inside the feature included an iron file, clear bottle glass fragments, square-cut nail fragments, and a lead ball. The feature appears to be a furnace or hearth, however, except for a few fragments of burned limestone and melted glass in the fallen material, the interior exhibits no signs of fire.


The two industrial, mining-related sites have a great potential to provide important information for this early period of mineral extraction in the Copper Country. Documentary evidence for the company's occupation of the Copper Harbor location is slight, and archaeological data from the sites may cast bright light on the company, its workers, and their techniques. The artifact assemblage may also reveal much about the transportation of goods, people, and minerals between the East Coast and Michigan's Upper Peninsula. Please feel free to contact Dr. Patrick Martin (pem-194@mtu.edu) or Michael Madson (mmadson@loucksmclagan.com) if you have any questions, ideas, or comments, would like additional information, or are interested in participating in future excavations at the site.