Sunset at Carlton Peak, North Shore Lake Superior

The sun about to set below the horizon from the top of Carlton Peak in northeastern Minnesota, along the north shore of Lake Superior. While by no means the tallest of the Sawtooth Mountains along Lake Superior’s North Shore, Carlton Peak is certainly the most distinctive. From a distance, it stands out as a lone high point, 924 feet above lake level, separate from the ridges to the north and south. The rock of Carlton Peak was formed deep under the earth’s crust. Molten rock cooled slowly, forming large green and pink crystals of anorthosite, an aluminum oxide mineral. About a billion years ago, this large block of anorthosite was rafted up on the magma that was forming the North Shore’s cliffs and rocks. Glaciers eventually eroded away much of the surrounding volcanic rock, but they couldn’t scrape away the hard anorthosite that formed Carlton Peak. U.S. Forest Service.