The Oak Openings Region
"One of America's Last Great Places"

Wild Blue Lupine
Wild Blue Lupine

Why is this area so special?

The Oak Openings Region of Northwest Ohio is a globally rare ecosystem declared by the Nature Conservancy as “One of America’s Last Great Places”.  

The region is much more than just Oak Openings Preserve Metropark

The Florida Everglades is on the same list as the this region. Who would have thought a sandy stretch of land in Northwest Ohio would be included with such prestigious company as the Everglades?  They are both included on the Nature Conservancy's list of America’s Last Great Places.

It is home to more endangered native plant species than any other place in Ohio. More than one-third of all Ohio’s rare plant species can be found here.

Consequently this part of Northwest Ohio has been a favorite place for botanists from all over the country (and world) to study the unique animal life and rare plants that grow here.

A recent success story of the Oak Openings is the reintroduction of the Karner Blue Butterfly.  It wasn't seen here since the late 1980s but is now back.

Where is it?

The Oak Openings Region is in the western portion of Lucas County, stretching in to portions of Fulton and Henry counties at the south end.  To the north is extends almost to the Ohio-Michigan line  It is a band of sandy soil that is approximately 22 miles long and varies from 3 to 5 miles wide.

See the map on right for exact locations.

How the region was formed

The Region was formed during the last ice age.  When the glacier that covered this part of the state began to melt it created a very large lake.  The lake has since been named Lake Warren. 

Map of the Oak Openings Region
Map of the Oak Openings Region
in NW OH

click here for downloadable map

As the lake waters receded the old beaches and sand dunes were all that remained.

Click Here for an interesting paper that discusses how the region was geologically formed.  It was written by some researchers at the University of Toledo.   

Land Characteristics

The sandy soil left by the lake helped to create one of the most unique ecosystems and habitats in the state of Ohio as well as globally. The depth of the sand is anywhere from inches to 20 feet deep. Beneath the sand is a thick layer of blue clay that water cannot penetrate.

That’s why in some areas there is standing water for much of the year and in other areas it is almost desert-like. On the sand dunes the water quickly filters through the sand down to the clay layer.

Where the sand is thin and the clay is only inches below, there is standing water and swampy areas for much of the year. It is only during the warm, dry days of summer and fall that the water dries up.

You will see high, dry sandy areas which quickly give way to wet, swampy areas. This transition is in a matter of feet. You can be standing on top of a sand dune looking down at a swamp.

The entire Oak Opening Region is like this, yellow sand dunes giving way to swamp forest or wet prairie.

These unique characteristics are the reason so many rare plants and animals live here.

Oak Openings Sand Dunes
Sand Dunes at Oak Openings Preserve
(Girdham Rd.)

Yellow Sand Dunes

The dry, hot sand dunes are not very hospitable places for most plants to grow. The plants that do grow in that kind of habitat are unique. Many of them don’t grow any where else in Ohio.

The plants that grow on the sand dunes have adapted to the extreme conditions. Plants like the prickly pear cactus thrive in the hot sand. That’s because they have long roots that work their way down to the water table below.

Other plants like wild lupine and bluestem grasses were once quite abundant. Open prairies full of colorful wild flowers, tall grasses, and sparse oak trees must have been quite a sight.

Black oak is the most prevalent oak tree that grows here. It likes the sandy soil and has adapted to the conditions.

Wet Swampy Areas

The same holds true for the wet, swampy areas adjacent to the dunes. The wet prairies are also home to many rare species of plants and animals not found any where else in Ohio.

The swampy spots come in a couple different forms.

Some swampy areas are covered with forest. These areas are swamp forest areas (appropriately named) and are typically full of pin oak trees, maple trees, black tupelo, and others.

Irwin Prairie
The sedge meadow at Irwin Prairie

There are still many swamp forest areas scattered throughout the region. They can be found on many privately owned wooded lots as well as parks and preserves.

They have remained over the years since the land was too wet to farm in the early days. Land owners didn’t bother to remove the trees.

Other swampy locations are open areas and considered to be wet meadows or wet prairies.

The best example of a wet meadow / wet prairie is Irwin Prairie State Nature Preserve. This prairie once extended for miles across western Lucas County. Only a small portion of of the original prairie remains today.

Unfortunately many of them have been destroyed by land owners and development of the area. Most of the wet meadows have been drained and filled in.

The Name Oak Openings

The name Oak Openings comes from early settlers who came through here on their way west.

After spending horrid days and nights trudging through the deep, thick muck of the Great Black Swamp they would have made their way to this area. What a welcome change the dry, open ground must have been.

The sand dunes would have had oak trees (mostly black oak) growing sparsely on the sand dunes.

Growing below the oak trees would have been sedge grass and little bluestem grass. These “openings” were referred to the settlers as Oak Openings.

Restored oak savannas still have this characteristic. They can be seen at Oak Openings Preserve, Kitty Todd Preserve, Secor Metropark, and some private residences.

Wood Lilly
State Threatened Wood Lilly

Native Americans

Humans have played a role in the Oak Openings Region for thousands of years. The Native Americans helped preserve the prairies and black oak savannas.

The natives saw the benefit of fire to the landscape. They saw that it was a critical component to maintaining the natural habitat. Fire would keep invasive plants and other brushy, woody plants from taking over the oak savannas.

With periodic fire the native prairie species, like wild lupine, could thrive without being choked out by larger woody plants.

Native Americans would set fire to the prairies to maintain food sources like wild blueberry. The open savannas attracted wildlife which made hunting easier. Food was more abundant.

Development of the Oak Openings

It wasn’t until the Europeans began settling this area and the natives were pushed out that the practice of fire suppression began.

When management of the land was no longer practiced the invasive plants began to take over. Over a period of time the savannas became overgrown. The grasses and wildflowers were choked out.

The rare ecosystem that had been thriving for thousands of years was starting to disappear.

The development of Northwest Ohio lagged behind the rest of Ohio as a result of the Black Swamp. This just wasn’t a great place to be in the early to mid 1800s.  Standing water was a breeding ground for mosquitoes.  Malaria was rampant.

As the area became more populated in the late 1800s and early 1900s drastic changes began to take place in the Oak Openings. The main objective of settlers was to create as much tillable farm land as possible. Standing water was in the way.

Hundreds of miles of ditches were dug in Lucas County to drain the water. Ponds were created. The wet meadows and prairies were filled in. Residential homes were built, and then commercial development began.

karner blue female
Karner Blue Butterfly
at Kitty Todd Preserve

Edwin Moseley

In the 1920s a naturalist from BGSU by the name of Edwin Moseley began studying the Oak Openings Region. He was the first one to define the area known today as the Oak Openings.

There are other sandy areas in Northwest Ohio that can be considered similar habitats. These are also as a result of the different stages of Lake Warren receding.  Some are near Bowling Green.  Others are further west in Fulton County.

But the area known as the Oak Openings Region today is the area in western Lucas County defined by Moseley.

He began studying and writing about the unique and rare plants and animals found here. He published many of his papers worldwide. Soon after, naturalists from around the world began coming to the Oak Openings Region to study the unique plants and animals.

It is Disappearing

Since Edwin Moseley’s work, the habitats of the Oak Openings Region have drastically been reduced in size and numbers.

Development continues. The Toledo airport destroyed hundreds of acres of Oak Openings Region land in the 1950s. Residential developments continue to destroy prairies and wet meadows.

The rare plants and animals that can only be found here in the state of Ohio continue to be at risk of disappearing forever.

Irwin Prairie
Oak Savanna at Oak Openings Preserve


The destruction of the Oak Openings isn't necessarily being done deliberately.  Many people just don't know what it is or why its special.  A rare plant to some is a weed to others.  A sand dune capable of sustaining a globally rare habitat is also a nice, dry building site for some. 

Fortunately the number of local residents who are familiar with the Oak Openings continues to increase. Local programs by the Toledo Metroparks, Toledo Zoo, and other local organizations continue to promote awareness.

The local Nature Conservancy office, located at Kitty Todd Preserve, operates a land registration program for home owners in the Oak Openings Region. This program recognizes home owners who make a conscious effort to conserve all or a portion of their land.

The return of the Karner Blue Butterfly and Wild Lupine to Kitty Todd and Oak Openings Preserve has done a lot to increase local awareness.

Hopefully man and nature can find a balance and what is left of the Oak Openings Region will still be here for future generations.

Living in the Oak Openings

As mentioned above, many home owners who live in the Oak Openings Region don’t fully appreciate where they live. 

I have lived in this sandy stretch of land in Northwest Ohio all of my life.  I never appreciated the uniqueness of this area until recently. 

To me it was just a dry, sandy area where grass wouldn't grow.  The dry sand dunes give way to low, wet, swampy areas.  The standing water makes it a breeding ground for mosquitoes in the summer months. 

As I became more interested in the nature of this area I came to realize that the residents here live in a globally rare ecosystem. 

I am now in the process of converting our 8 acres back to its native state.  My family thinks I’m nuts but I’m OK with that.  I’m having fun and doing something to preserve our area.

Where to see the features of the Oak Openings Region

There are many great ways to see and appreciate this unique area.  Places to visit and things to do to get a look at what the Oak Openings Region is all about are listed below.

Secor Metropark
Wildwood Metropark
Maumee State Forest
Kitty Todd Preserve
Irwin Prairie
Wabash-Cannonball Trail (The sections that run through the region. Most of the south fork is in the region)
Nature Photography
The Scout Trail

Free Book About Living in the Oak Openings

If you live in the this region you can get a free book from the Nature Conservancy.  The following link will tell you how to get it:  Living in the Oak Openings; A Homeowners Guide to one of the World’s Last Great Places.

There is so much to read about how the area was formed, why it is in trouble, and what it being done to save it.  This all very important in order gain a true appreciation of how special this area is.

Additional Information

-  The US EPA has a great site about how the region was formed and why it is so unique.  (There is a lot of “academic” information)

Read more about what is being done locally to save the region.

-  Click here for a downloadable map of the O.O. Region (PDF file)

-  The following link is a very interesting  3 minute video clip all about the region.  It was produced by WGTE public television in Toledo, Ohio.  (Make sure you have a high-speed Internet connection since it’s a large file.)

NW Ohio Nature Oak Leaf