From the road, it doesn’t look like much. The largest known piece of float copper in the world merely looks like an enormous rock sitting on a mound of grass.
The sign next to this piece of float copper is unassuming and, when people are driving around Presque Isle Park in Marquette in Michigan’s Upper Peninsula, it’s easy to miss.
But the story behind this float copper is one of action and continued uncertainty.
Editor’s Note: This article was originally published in 2012. Since that time, the world’s largest piece of float copper was sold to Bryan Lees of Collectors Edge Minerals, Inc., and as best we can determine, it no longer resides in the U.S.
What is Float Copper?
Float copper is the term first used in 1924 to describe glacially transported native copper in the western Upper Peninsula. It can be easily identified by its bright green to black alteration crust that consists of malachite, cuprites, and other minerals.
The History of Float Copper in the Upper Peninsula
It was discovered as landowners in the Keweenaw Peninsula went over their new land with a metal detector. They were astonished by the size of what they found: a 15 x 13-foot piece of glacial float copper.
The Keweenaw Peninsula is often called “Copper Country” because of the amount of copper and its ore that was mined in this area. In fact, at 90 percent pure, much of this copper is the purest in the world, and this is what makes this piece of float copper so remarkable.
In the early 2000s, Fred Rydholm heard about the immense artifact. Rydholm was a popular local historian who was known for being very knowledgeable about Marquette County; he was often called to tell stories about some of the area’s most influential people.
He was also very interested in natural history, and when he went out to visit the float copper, he was captivated by it. He convinced the landowners that, instead of selling it to be melted down for wiring or other material goods, they should preserve it.
They agreed to work with Rydholm to do just that, as long as they eventually got their money for it – which turned out to be a grand total of $250,000.
Raising this sum was an important effort for Rydholm, “because he’s a historian, and this is part of the area’s history,” says his wife June, who still lives in the house that Rydholm built in Marquette.
Preservation of Upper Peninsula Float Copper
Fred Rydholm created an organization called the Ancient Artifact Preservation Society, which helped to raise the money.
Sadly, they weren’t able to raise it before Fred died in 2009, and June and some friends who have been involved in the organization since its inception have since taken on the task.
To help raise awareness of the float copper, the AAPS decided to bring the copper to Marquette, which was a considerable undertaking. “We felt that Fred Rydholm was more well known here and he was the push behind this, so therefore the copper should be [in Marquette],” June Rydholm says.
Moving the Float Copper to Marquette Michigan
A number of contractors volunteered their time and resources, or greatly discounted them, and on September 3, 2010, the copper was moved. Huge cranes were used to drag it through the Calumet woods and lift the 28.5-ton rock onto trucks.
As the trucks drove through the narrow Upper Peninsula streets, roads had to be closed ahead of time.
“It was exciting. Can you imagine that big piece of float copper coming through the narrow streets of Hancock?”, says June Rydholm, “and they did it – they moved it right into Marquette, and we were all very excited about having it here. It was very nice to see it.”
Float Copper on Display at Presque Isle
Until 2016, this float copper sat on a raised mound of grass, with a sign that recalls the importance of Fred Rydholm in preserving the copper. Rydholm would be proud of the artifact’s impact: he was an educator and liked to teach people about the importance and history of this area.
June Rydholm says that while the copper was in Presque Isle, entire classes visited it to learn about float copper and the receding glaciers that once covered the U.P. Without her husband Fred’s efforts, “the teachers wouldn’t have even approached that subject about the glacier, but now they are,” June Rydholm says.
But even though the copper was moved to the Rydholms’ hometown, it was not there permanently – in 2016, the world’s largest piece of float copper was sold to Bryan Lees of Collectors Edge Minerals, Inc.
A new piece of float copper weighing more than 400 pounds was installed at Presque Isle along with a plaque in memory of Mr. Rydholm in 2017.
Add visiting the Float Copper to your bucket list of things to do in Marquette Michigan this year!
This article was written by Lucy Hough in 2012.