Cliff Mine dump
After leaving the Central Mine, I drove to the Cliff Mine. It’s located on the west side of Cliff Drive, which runs parallel to US 41 and intersects it at both ends. The dump is near the north end of Cliff Drive. GPS coordinates are lat. 47 deg. 22.347’, lon. –88 deg. 18.747’. There’s a small stream running along the edge of Cliff Drive, actually more of a drainage ditch. I wouldn’t suggest trying to cross it in a passenger car, but trucks had no trouble. After crossing the ditch there’s an area for parking, and another shallow stream (in the picture) before the dump. We were asked not to drive across the stream, but it was shallow enough to drive through.
This is an old and well known mine. It was the first major producer in the copper country, operating from 1835 to 1870. The dump is quite extensive, but has been picked over.
There is copper in leaf form running through the host rock, but the micro copper crystals are found in vugs in prehnite. I picked up a lot of prehnite to break up and leach with acid after returning home. When I did so, I found a few good copper crystals, nice prehnite in blocky prisms, quartz, pumpellyite, a few fairly good epidotes, and a couple of chalcocites.
Although the collecting wasn’t the best, it was an enjoyable afternoon. I spent some time on the slopes of the dump talking with an old friend, Joe Heyman. Joe had lived in the Houghton area, but had moved a few years ago to El Paso, Texas. He had come back to the UP for a visit, timing it nicely to coincide with Keweenaw Week.