COMING SOON: Keweenaw Historic GeoTrail!
This twenty cache trail will lead you on an adventure through Keweenaw National Historical Park and many of its partner Heritage Sites. We hope you enjoy the beautiful sights as you explore the copper mining history, connect with the people involved, and discover the unique geology that made it possible. Don't forget to record the portion of the cypher key hidden in this cache. Click or scan the QR code to download the Keweenaw Historic GeoTrail Passport, or click here to learn more.
NOTICE: This cache is placed with permission of the Porcupine Mountains Wilderness State Park. Please be respectful of park rules; failing to do so may jeopardize the future of geocaching in this park.
The Union mine was originally opened in 1846 by the Isle Royale and Lake Superior Mining Company. It consisted of two shafts, one on each side of the Union River.
In 1864 Alexander Hamilton Sibley purchased the Union Mine property and began redeveloping the mine.
According to the 1902 publication of "The Copper Handbook" Sibley had a choice between two locations to purchase, the Calumet Conglomerate for $60,000 or the Union Mine for $100,000.
Incidentally, the Calumet Conglomorate would go on to produce over 4.2 billion pounds of copper, making it the most productive lode in the state, while the Union's most productive year was only around 9,000 pounds of copper and was later abandoned as non-profitable.