Another star trail photo, as I work to refine my technique. These are stars rotating over the ruins of the Isle Royal #6 rockhouse. A massive steel structure once rose above these huge cement foundations, processing rock from the nearby shaft. Trains would pull through the slot between these walls to cart away copper-bearing rock to the mill.
Amusingly, the shaft (safely capped) is currently directly under a major snowmobile route. It's a logical shortcut between the main trail and the highway, and the cap isn't visible under all the snow. I only knew where to avoid it (more out of excess carefulness than actual need for safety) because I've been here in summer so often.