ELY, Minn. — It’s the kind of July day that Minnesotans fantasize about in the dead of winter. Puffball clouds float in a blue sky and daisies sprout under stately pines lining Spruce Road, the main artery of an old logging network deep in the Superior National Forest about 15 miles southeast of Ely. Paul Schurke is bumping down a dirt road in a Dodge Ram pickup truck. He owns Wintergreen Dogsled Lodge with his wife, Susan, and is famous in these parts as the explorer who co-led the first dogsled expedition to the North Pole without re-supply in 1986.

The dirt track ends before it reaches the Boundary Waters Canoe Area Wilderness, the roadless, motorless, cellphone-towerless 1.1-million-acre ecosystem where nearly 250,000 visitors from around the globe annually pilgrimage to paddle a connected chain of more than 1,000 pristine lakes. Every night they break camp on a forested shoreline to hear the cool northern breeze whisper through the pines and loons project their mournful calls over vast stretches of open water. Occasionally an emerald display of Northern Lights flickers in a sky entirely free of light pollution.

He hops out of the truck and hikes toward four bright red poles sticking five feet out of the ground.

“Just beyond those trees is Gabbro Lake, one of the holiest of holy walleye lakes in the Boundary Waters,” says Schurke.

If only this were an outing to fish for walleye. Instead, Schurke is standing on a test-mine site where a dystopian scene could unfold over the next few decades. It’s where Twin Metals Minnesota, owned by the Chilean company Antofagasta, proposes to build the largest underground mine in the state’s history.

Mining has fueled this region known as the Iron Range for more than a century. Ely’s first iron-ore mine opened in 1888. But Twin Metals plans to mine copper sulfide ore and other precious metals, which has never been done in Minnesota. To mine copper sulfide in such a water-rich environment, says Schurke, would be “a worst-case-scenario nightmare.”

Schurke climbs back into his truck, turns around, and drives down Spruce Road to Voyageurs Outward Bound School. Campers have been learning how to survive in the wilderness here since 1964. The smell of fresh bread wafts down to the bank of the Kawishiwi River, where a group of teens is launching a 21-day expedition into the Boundary Waters. Schurke launches another canoe and we paddle downriver.