Pittsburg and Isle Royale

Poor rock pile, Pittsburg and Isle Royale, Rakestraw collection, ISRO Archives.

his company, incorporated in Pittsburg about 1846, began its mining activities in 1847 in the Todd Harbor area. In that year two log cabins and a blacksmith shop were erected, and nine men worked on a shaft near the shore. The following year they made other explorations, mostly near the shore, but one about a mile south of the shore. Here they reached a depth of 225 feet and then found the pumps unable to cope with the water. By 1849 they struck profitable veins, mostly mass and barrel-work, near the lake and later had 25 men employed and a stamp mill under construction. Their last year of recorded production was 1853; they apparently closed operations because of the isolated location and lack of protection from northerly gales.