Central Mill

When mines decided where to place their stamp mills they considered three important factors: a constant supply of water; a large dumping ground for tailings; and the proximity to the mine itself. For the early fissure mines along the Keweenaw, the first concern was location. The boom and bust nature of fissure deposits on which these mines were built meant that companies were not willing to spend large amounts of money on building miles and miles of railroad tracks to transport their copper to distant mills. The solution was to find the nearest supply of water and build the stamp mill there – the closer to the mine the better. For the Central Mine, this meant placing their mill near the East Branch of the Eagle River.

The mills built during the Copper Country’s adolescence were small and crude affairs, especially when compared to their massive concrete and steel ancestors. There were structures built almost entirely with wood and as such rarely survived through the decades. Because of this, no step-stair concrete levels greeted us as we approached the Central Mill – no large concrete foundations or machine mounts. It’s history was not shouted from atop a concrete pillar – but whispered along small pieces scattered about the ground. Scattered across the gravel floor – among a carpet of sun-bleached wood splinters – were clues to another time. You just had to pay attention.

Early stamp mills were a very crude affair. Before the advent of leaching, floatation, Wilfley Tables or buddles, mills relied on only one tried and true technology: the Cornish Stamp. These early stamps relied primarily on gravity to do all of the work. While these stamps did the trick, they were not very efficient. A stamp of this design could only work about 2 tons of rock per day, creating huge bottlenecks in production. By the late 1850’s, the more efficient steam driven stamps were being placed into service. These newer steam powered stamps could crush up to 125 tons per day – a significant improvement. Sitting at the dawn of this new technology – and at the end of the Cornish Stamp era – is the Central Mill, built around the mid 1850’s.