About the same time the Egyptian pyramids were built, prehistoric American Indians were using primitive methods to mine copper in Michigan’s Upper Peninsula.

In a new book, former Michigan state archaeologist John R. Halsey draws deeply from early newspaper sources, notes from explorers and expedition summaries to flesh out who the miners were, where they came from, how they extracted copper and how it was used.

Halsey also attempts to answer the questions: Why did they stop and where did they go?

“Prehistoric Copper Mining in Michigan” has more than 200 pages of appendix and bibliographic material detailing the names of the explorers, the location of the mine they discovered and the date it was discovered.

The first “official” discovery of these ancient mines occurred in the 1840s. Samuel O. Knapp, a mining agent for a firm that would later become Minnesota Mining Company, was exploring land near Ontonagon when he discovered an unusual depression in the soil. After clearing away debris, he and his fellow explorers discovered crude hammer-stones and chisels used to mine a copper vein.

Another depression was found and, after clearing a trench, a large mass of copper was found suspended on wooden support beams. It was deduced that early miners lacking heavy equipment could only mine protuberances, and left the remains behind.

With these discoveries, Michigan’s copper boom, which would become bigger in dollar value than the gold rush, was on.

According to Halsey, hundreds of ancient mining sites were discovered in Michigan between the 1840s and 1850s. They were mostly on Isle Royale and in the counties of Houghton, Baraga and Ontonagon.

“The ancient mining sites served as guideposts for modern miners, and within 25 years any record of the prehistoric mines had been destroyed,” Halsey said. “There was nothing left to be researched.”

He said this was despite “colossal diggings” left behind by the miners — some as large as 37 feet deep and 70 feet long. Although mines of this size seem nearly impossible to dig with primitive tools, “the ancient miners had thousands of years to do it,” Halsey said.

Halsey said why they stopped isn’t known. He surmises a possible drought caused the ancient miners to move away. Halsey also believes that the ancient miners were only onsite for a few months a year, due to the prohibitive weather in the Upper Peninsula.

Explorers also found millions of hammer-stones disposed of in the mines, which, because of their condition, were replaced and left behind in the pits. They also found charcoal and remnants of fire being used to heat and crack rocks to get to the larger pieces of copper.

It is thought that the mined copper was used for decorative bangles on regalia, and also for spears, fish hooks, knives and chisels after it was pounded flat by the miners.

Halsey speculates that much of the mined copper, estimated in millions of tons, was used for trading. He said a large volume of copper caches of spear heads, knives and nuggets have been found all through the Midwest.

“The caches were buried a couple inches underground. They were clearly being taken somewhere and it didn’t get to where it was going, or they didn’t come back to get it,” Halsey said.

What wasn’t found is perhaps more important than what was. There were no campsites, writings or burial remains near the mines, so little is known about the daily life of the prehistoric miners.

Although the earliest recorded discoveries date to the 1840s, Halsey said an obscure, but important letter written by Samuel Preston, a friend of Benjamin Franklin, seems to offer proof that copper in the Peninsula was discovered much earlier by French explorers In a 1829 letter to the New York American, Preston details how, when finalizing the Paris Peace Treaty of 1783 with England, Franklin described the line being drawn through Lake Superior as giving the U.S. access to copper, which he said, “would be the greatest service rendered to his country and the copper a greater source of wealth than any other country possessed.”

Halsey’s book also uses more modern-day archaeological research that was conducted at a number of mining sites in Keweenaw and Ontonagon counties and at Bois Blanc Island, Michigan, and Summer Island, Wisconsin. Research has verified that the earliest copper mining tools date to 7000 B.C., but the earliest sites with direct evidence of copper mining date to the late Archaic Period (5000- 3000 years ago).

Halsey’s new book, which pretty much covers and details all known information on the prehistoric copper mining, will certainly make it easier for students of archaeology as they undertake field work.


John R. Halsey Book Signing

Free, Saturday, Nov. 10, 1 p.m. to 2 p.m., Library of Michigan 702 W. Kalamazoo St., Lansing www.michigan.gov/ libraryofmichigan (517) 335-1477