Field milkwort is another plant that shares the Sibley Prairie. Sibley is an area of old lake bed, left to us by the retreat of what is now Lake Erie. Geologically speaking, Michigan is on the rise, freed of the weight of glaciers. I figure in my life it will rise about an inch. That is why the Great Lakes are slowly retreating, although right now people along Michigan shores would like to speed things up. The lakes are at record highs.