Adventure Mine

This poetically named copper mine, in a scenic area, is again open for underground and surface tours. Its energetic new owner-operators are two youngish Michigan Tech grads, Matthew and Victoria Portfleet. She's a survey engineer by training. Matthew enjoyed exploring Copper Country's old mine sites so much that he switched his major to mining engineering (now discontinued). The Portfleets have added to tours developed by the Adventure Mine's former owners, John and Winnie Neph, now retired. For instance, rappelling down a mine shaft with rope and harness is a highlight of the Miner's Underground Tour ($50, 3 hours in all), after half an hour of training and safety instruction.
Two short tours are given regularly during open hours. The 45-minute Trammer's Underground Tour ($10) takes a mostly level route into the mine via a horizontal adit (instead of going down a vertical entrance shaft). ??A vehicle with a big step up takes visitors to the entrance. The path inside the mine involves some uneven ground and one area where a little stooping is required.. Once underground, visitors get to see several mine stopes (room-like excavated mining areas) by candlelight. Far above, the guide's light picks out clusters of bats snuggling up, two and three abreast. (They seldom fly around, and their teeth can't penetrate human skin.) It's easy to imagine the sound of falling rock after the captain lit explosive fuses at the end of each shift. A bonus is the spectacular view to the east, high above the treetops. ?
The Historical Surface Tour ($10), also 45 minutes of easy walking, passes several adits and shafts, a cold air shaft's "ice cave," and pit mines made by prehistoric miners. Children are $6 each on these tours. Combine the two for $15/adult, $9/child.

Curious children and adults and serious aficionados of geology and minerals may well prefer the more detailed, longer two-hour Prospector's Underground Tour ($21, or $12/child, advance reservations suggested). It uses a different entrance and involves uneven ground and crawling through some tight spots.

The underground tours are especially pleasant on hot, rainy, or buggy days, since the mine temperature is always 48 degrees. Bring a jacket, and wear closed-toe shoes for good footing. Headlamps on visitors' helmets provide the only light. Formations of oxidized copper, calcite, epidote (green), and feldspar (red) can be seen on the mine walls..

For all tours, participation is at the operator's discretion. See Adventure Mine site on Ontonagon chamber site for info on children on tours, and info on bats at this bat-friendly mine. The gift shop includes rocks and copper jewelry, mineral specimens of course, and books on bats, on the area's history and mining. Snacks and beverages are available, and picnic tables are outside

Why the money was made in Keweenaw copper, not Ontonagon County's
The Adventure Mine, first explored in 1850, is typical of early Euro-American mining attempts that worked rich veins charged with mass copper. They followed the traces of prehistoric miners who started mining surface outcrops of copper. The Adventure Mine's surface tour shows where ancient miners built fires to heat surface rock, then threw hot water on it and beat it with hammers to release the copper.

Ontonagon County's Yankee miners in the 1840s and 1850s didn't realize was that these copper-rich veins were unevenly distributed. Even good veins could give out suddenly. The big profits in copper were made later, along the 5-mile-wide fault line of the Keweenaw Peninsula, by companies large enough to afford the technology to extract copper from the less copper-rich amygdaloid formations (where the copper formed in small bubbles of volcanic rock) and conglomerate formations (where copper minerals were formed from gasses that filled the small cracks and spaces in conglomerate rock).

The first Adventure Mine investors, in 1850, were already among the lucky few who had struck it rich in Upper Peninsula copper at the Cliff Mine near Eagle River, another fissure or mass copper vein. Into the 1900s mining officials remained focussed on getting big pieces of copper and tried to impress investors with state-of-the-art equipment and substantial buildings. (Italian stonemasons crafted the stone buildings whose foundations are seen today.)

Here at the Adventure Mine, "they invested millions and never paid a dividend," says former mine owner John Neph. "It always showed a lot of promise"— just enough to keep investors putting in a little bit more, in hopes of a payoff. All told, the mine produced $2.5 between 1850 and 1917, something like $80,000.000 today. Copper mined here was shipped by rail all the way to the stamp mill at Edgemere north of Freda (on Lake Superior west of Houghton), then taken to the Quincy Smelter at Ripley next to Hancock.

At the east edge of Greenland on M-38, clearly signed. (M-38 connects Ontonagon with Baraga. It's 1 mile west of M-26 connecting Houghton to Bruce Crossing.) Open from mid-May through color season. Mon-Sat 9 a.m. to 6 p.m., Sun 11-6. (906) 883-3371. Handicap-accessibility: call.
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