Tiffin River at Goll Woods State Nature Preserve in Ohio

The Oak Openings Region is a globally rare ecosystem composed of over of Michigan and Ohio. The land consists largely of

oak savanna An oak savanna is a type of savanna—or lightly forested grassland—where oaks (''Quercus ''spp.) are the dominant trees. The terms "oakery" or "woodlands" are also used commonly, though the former is more prevalent when referencing the Mediter ...

and grassland prairie. It is considered by

The Nature Conservancy The Nature Conservancy (TNC) is a global environmental organization headquartered in Arlington, Virginia. it works via affiliates or branches in 79 countries and territories, as well as across every state in the US. Founded in 1951, The Natu ...

as having a similar ecological importance as the

Florida Florida is a state located in the Southeastern region of the United States. Florida is bordered to the west by the Gulf of Mexico, to the northwest by Alabama, to the north by Georgia, to the east by the Bahamas and Atlantic Ocean, and to ...

Everglades The Everglades is a natural region of tropical climate, tropical wetlands in the southern portion of the U.S. state of Florida, comprising the southern half of a large drainage basin within the Neotropical realm. The system begins near Orland ...

and is one of the 200 "Last Great Places on Earth". This unique area was formed after the last ice age when the continental

glacier A glacier (; ) is a persistent body of dense ice that is constantly moving under its own weight. A glacier forms where the accumulation of snow exceeds its Ablation#Glaciology, ablation over many years, often Century, centuries. It acquires dis ...

melted leaving behind a large lake called

Lake Warren Lake Warren was a proglacial lake that formed in the Lake Erie basin around 12,700 years before present (YBP) when Lake Whittlesey dropped in elevation. Lake Warren is divided into three stages: Warren I , Warren II , and Warren III , each defined ...

. Over time, this lake was gradually reduced to present day

Lake Erie Lake Erie ( "eerie") is the fourth largest lake by surface area of the five Great Lakes in North America and the eleventh-largest globally. It is the southernmost, shallowest, and smallest by volume of the Great Lakes and therefore also has t ...

and left behind a large tract of sandy soil to the west. The area was frequented by

wildfire A wildfire, forest fire, bushfire, wildland fire or rural fire is an unplanned, uncontrolled and unpredictable fire in an area of Combustibility and flammability, combustible vegetation. Depending on the type of vegetation present, a wildfire ...

s that only the thick-barked

oak An oak is a tree or shrub in the genus ''Quercus'' (; Latin "oak tree") of the beech family, Fagaceae. There are approximately 500 extant species of oaks. The common name "oak" also appears in the names of species in related genera, notably ''L ...

trees could survive. When pioneers arrived after first crossing through the

Great Black Swamp The Great Black Swamp (also known simply as the Black Swamp) was a glacially fed wetland in northwest Ohio, sections of lower Michigan, and extreme northeast Indiana, United States, that existed from the end of the Wisconsin glaciation until th ...

they called the area the "Oak Openings" as a comparison to the thick swamp. Today, the

Oak Openings Preserve Metropark Oak Openings Preserve Metropark is a nature preserve located in Swanton Township, Ohio, owned and operated by Metroparks Toledo. Most of the park is an oak savanna ecosystem, characterized by alternating wetland and vegetated dunes. The park hos ...

is the largest intact piece of mostly dry savanna remaining. The largest sections of swamp and savanna, are in the hands of citizens Goll Woods State Nature Preserve also protects a small area of Oak Openings.Goll Woods Walking Guide
OhioDNR.gov. Retrieved 29 March 2016

References

Further reading