In the densely forested and thinly populated region of Michigan’s Upper Peninsula, Adventure Mine Tours provides several options for touring a historic copper mine. Those who sign up for tours put on hard hats with headlamps to walk and rappel through an 1860s mine to learn about the old-time ways of early miners.  But, make no mistake, bat conservation is part of the mine’s message.

a tricolored bat in flight
Tricolored bat. Photo by J. Scott Altenbach.

Adventure Mine owner Matthew Portfleet has witnessed the wrenching decline of little brown bats (Myotis lucifugus), big brown bats (Eptesicus fuscus), northern long-eared bats (Myotis septentrionalis) and tricolored bats (Perimyotis subflavus) due to White-nose syndrome, a debilitating often fatal fungus that has decimated huge populations of bats across the U.S. 

Portfleet recounts seeing thousands of hibernating bats in the mine during cold weather months when he was a college student several years ago. He now talks to mine visitors about dwindling numbers of bats and the need to save them. In addition to running his tour operation, Portfleet has become actively engaged in bat conservation. Using standards established by Bat Conservation International, Portfleet builds bat gates that allow bats to fly freely in and out of mines and caves while restricting human access. His gates are now commissioned by the U.S. Forest Service and Michigan’s Department of Natural Resources.


  • Adventure Mine offers four types of tours, beginning in May through the summer months. The tours are offered seven days a week.