History of the Cliff Mine

Sketch of the Cliff Mine, 1849. (image courtesy of Michigan Tech Archives)

The Cliff Mine, owned and operated by the Pittsburgh & Boston Mining Company, was the first successful copper mine in the Upper Peninsula of Michigan. Discovered in 1845, the “Cliff Vein” produced over 38 million pounds of refined copper over a 40 year period, and paid dividends to its investors totaling $2.5 million.

In 1843, the United States government officially opened the Upper Peninsula to mining operations. This lead to a flood of adventurers, prospectors, and speculators to the area, each hoping to strike it rich. One group of investors, half from Pittsburgh, half from Boston, managed to acquire three leases in the Keweenaw, the northernmost part of the Upper Peninsula. This Pittsburgh & Boston Copper Harbor Mining Company would be the first miners to sink a shaft in the region, located at Hay’s Point in Copper Harbor. By the end of 1845, the company had sunk over $28,000 into their Copper Harbor lease, only managing to extract $8,000 in refined copper. Their copper mining adventure looked to be a failure.

At the same time at their as of yet neglected second lease, a narrow vein of copper bearing quartz was discovered at the top of a 200 foot basalt cliff. It didn’t look very promising at this point, but as the vein was traced to the base of the cliff, a discovery would be made that would astound the world. After digging into the bluff a distance of 70 feet, a group of German miners would uncover a massive boulder of pure copper, and the Cliff Mine was born.

The Cliff, and the majority of early mines in the area, focused on fissure lodes, where large masses of pure metal, often weighing many tons, could be found running vertically downward into the earth. These masses, too large to be raised from the mine whole, had to be chiseled apart over the course months, until they were of a manageable size to be lifted out of the mine by the use of a horse-powered whim. The Cliff’s early success occurred when nearly all of the mining work performed on the peninsula was powered by horse and water-wheel. Steam power existed, but the expense was too great for most mining ventures and their investors. the discovery of the “Cliff Vein” provided assurance to other mining companies in the Upper Peninsula that there was money to be made, and that investment in infrastructure and steam power could be justified.

From 1846-1858, no other copper mine in the region could match the production of the Cliff Mine. Even as mining activity transitioned from fissure lodes to the longer lived conglomerate and amygdaloid lodes made famous by the Calumet & Hecla and Quincy Mining Companies, the “Old Cliff” remained profitable. After the Civil War however, the depth of the mine (1000 feet!) and the course of the vein northward under the bluff meant that maintaining a self-sustaining operation was becoming more difficult. By 1870, the company decided the mine, though still producing, was not worth further investment, and sold the mine for $100,000.

Activity at the Cliff continued for the next 60+ years under various management, but it never managed to regain its earlier success. In the 1920’s and 30’s, the new owners of the Cliff, the Calumet & Hecla Mining Company, were still hoping a new vein would be uncovered, and drilled dozens of holes throughout the property. Unfortunately, nothing of promise was found, and by the 1950’s, all interest in the Cliff as a producing mine ended.