Skull Cave is a small and shallow cave on the central heights of Mackinac Island. The cave was carved during the Algonquin post-glacial period by waters of Lake Algonquin, a swollen meltwater ancestor to today's Lake Huron. It is believed to have been used as an inhumation site by Native Americans of the Straits of Mackinac area in the 1700's. The cave was also used as a refuge in 1763, by fur trader Alexander Henry, a survivor of the capture of Fort Michilimackinac by Native Americans allied with Chief Pontiac. Henry even wrote about about this cave in his memoirs. This island has several other small caves such as: Crack in the Island, Cave in the Woods, and Devil's Kitchen.