Within Keweenaw National Historical Park's Quincy Unit are the former Quincy Mining Company properties, including the sites of the mine shafts, hoist houses and the copper smelting complex on the shore of Portage Lake. Much of the former Quincy Mine was designated as a National Historic Landmark District in 1989. When Keweenaw National Historical Park was established in 1992, Congress recognized the former Quincy Mine as one of the components that best represents the story of copper mining on Michigan's Keweenaw Peninsula.

Copper mining on the Keweenaw Peninsula pioneered deep shaft, hard rock mining, milling, and smelting techniques and advancements in related technologies later used throughout the world.
...extraction and processing are best represented by extant structures of the Quincy mining Company.
From Public Law 102-543