Myths and Legends of our Own Land, by Charles M. Skinner, , at sacred-texts.com
There were many water gods about Lake Superior to whom the Indians paid homage, casting implements, ornaments, and tobacco into the water whenever they passed a spot where one of these manitous sat enthroned. At Thunder Cape, on the north shore, lies Manibozho, and in the pillared recess of La Chapelle, among the Pictured Rocks, dwelt powerful rulers of the storm to whose mercy the red men commended themselves with quaint rites whenever they were to set forth on a voyage over the great unsalted sea. At Le Grand Portal were hidden a horde of mischievous imps, among whose pranks was the repetition of every word spoken by the traveller as he rested on his oars beneath this mighty arch. The Chippewas worked the copper mines at Keweenaw Point before the white race had learned of a Western land, but they did so timidly, for they believed that a demon would visit with injury or death the rash mortal who should presume to pillage his treasure, unless he had first bestowed gifts upon him. Even then they went ashore with fear, lighted fires around a surface of native copper, hacked off a few pounds of the softened metal, and ran to their canoes without looking behind them.
There was another bad manitou at the mouth of Superior Bay, where conflicting currents make a pother of waters. This spirit sat on the bottom of the lake, gazing upward, and if any boatman ventured to cross his domain without dropping a pipe or beads or hatchet into it, woe betide him, for his boat would be caught in a current and smashed against a rocky shore. Perhaps the most vexatious god was he who ruled the Floating Islands. These islands were beautiful with trees and flowers, metal shone and crystals sparkled on their ledges, sweet fruits grew in plenty, and song-birds flitted over them. In wonder and delight the hunter would speed toward them in his canoe, but as he neared their turfy banks the jealous manitou, who kept these fairy lands for his own pleasure, would throw down a fog and shut them out of sight. Never could the hunter set foot on them, no matter how long he kept up his search.