Great Lakes Mesoscale convective complexs or MCCs can cause damage to wide swaths of forest and shatter glass in city buildings. These storms mainly occur during the night, and the systems sometimes have small embedded tornadoes, but more often straight-line winds accompanied by intense lightning. Historically, the Great Lakes, in addition to their lake ecology, were surrounded by various forest ecoregions (except in a relatively small area of southeast Lake Michigan where savanna or prairie occasionally intruded). Logging, urbanization, and agriculture uses have changed that relationship. In the early 21st century, Lake Superior's shores are 91% forested, Lake Huron 68%, Lake Ontario
Great Lakes region Hudson, Mohawk and Susquehanna form an arc of watersheds east to The Atlantic. The Great Lakes region, as distinct from the Great Lakes Basin, defines a unit of sub-national political entities defined by the U.S. states and the Canadian Province of Ontario encompassing the Great Lakes watershed, and the states and Province bordering one or more of the Great Lakes. Prior to European settlement, Iroquoian people lived around Lakes Erie and Ontario, Algonquian peoples around most of the rest, and a variety of other indigenous nation-peoples including the Lakotan, Ojibwa, Illinois, Pottawatmie, Huron, Shawnee, Erie, Fox, Miami, Crow and Ho-Chunk