The Oak Openings Region is unlike any other region in Ohio, where the eastern hardwood forest meets the western prairie to form a blend of habitats that sustain many rare species. Its diversity includes sand, clay, dunes, woodlands, floodplain, and fire-adapted savannas and prairies. Settlers traveling west in the early 1800s emerged from the Great Black Swamp that covered much of northwest Ohio and found a more hospitable setting, with oak trees spaced far enough apart to drive wagons between them. Scientists call the broad oaks towering over grasses and wildflowers oak savannas, while settlers called them the Oak Openings.