Long before freighters sailed Lake Michigan, the Anishinaabek traveled the mishingamaa, or large water, in birchbark canoes, following the lakeshore and landmarks such as the Sleeping Bear as guides along a network of water trails used for trade and seasonal migrations. In their belief, Mishipeshu, a great underwater panther, made waves by thrashing its tail, and storms were the work of Animikiig, the thunderbirds, so they painted symbols of both spirits on their canoes for protection. European settlers later adapted these routes for cargo and passenger travel. Since the early 1800s, thousands have entered the Manitou Passage, a gauntlet of shoals between the islands and the mainland, with some seeking shelter in South Manitou Island harbor and most using the passage as a shortcut. Many did not survive, and archaeologists have discovered at least 60 wrecks, while an untold number of ghost ships remain lost below the waves.