Ottawa National Wildlife Refuge

14000 W State Route 2
Oak Harbor , OH 43449

419-898-0014   |
The visitor's center is open 9 a.m. to 4 p.m. daily and all trails are open from dawn until dusk.

The Great Black Swamp and its Legacy

Northern Ohio’s preserved wetlands have a rich history that visitors can interpret and enjoy when they visit Ottawa National Wildlife Refuge.

The Ottawa National Wildlife Refuge is Ohio’s only federal wildlife refuge and represents a small portion of the area’s reclaimed wetlands. Northwest Ohio was once covered by a dense forest and thick swamp land. In certain areas the swamp water was so deep, a person could stand and be covered up to their chest. As the leaves on the massive trees changed, they would fall into the surrounding water and it would turn a deep black color; thus, it came to be known as the Great Black Swamp. The swamp was a product of the Pleistocene Epoch’s Pre-Illinoian glaciations that formed over North America. Ohio was once covered by the Wisconsinan glacier that began retreating 18,000 years ago. During its 4,000-year long retreat, the glacier did not move regularly, and its path carved through the land underneath, paving the way for Ohio’s varying topography and the creation of the Great Lakes. This region was flat with deposits of clay sediments left behind by the melting sheet of ice, making the ground impermeable. Original lakes formed by the glacial movement were much larger and covered more land than those today but overtime the lake water receded and Ohio’s current shore land resurfaced. What resulted was the foundation for the Great Black Swamp and the state’s marshlands. Settlement of the area was difficult because of the foreboding difficulty of clearing the swamp for farming, which was the impetus for western migration in the age of the frontier. Even native inhabitants found higher ground to settle, though they did venture into the swamp to hunt its robust wildlife, particularly the species of bird that flocked there. During the nineteenth century, settlement of the region exploded, and by the 1850s the swamp was rapidly being cleared for farming and development. Though the majority of settlers saw the swamp’s value as potential farmland, hunters were some of the first to see the value in its preservation. By the early 1900s duck hunters began purchasing marsh land to establish private hunting clubs, which were later acquired by state and federal wildlife division’s that now manage Ohio’s wetlands. It is because of the efforts made hunters to protect the area’s natural landscape that these wetlands continue to exist today. Ottawa National Wildlife Refuge was established in 1961 to conserve the wetland habitat and protect wildlife and plant species.

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Notes for Travelers

Similar to its neighbor, Magee Marsh Wildlife Area, Ottawa National Wildlife Refuge sustains a diverse wildlife population, most notably bald eagles, warblers, and wintering tundra swans. Binoculars, field guides, and trail maps are available at the visitor’s center to allow travelers the opportunity to participate in birding activities. Trails are open for self-guided tours and the refuge has an event calendar available on its website listing programs for all ages, such as eagle bus tours and Saturday nature crafts, stories, and walking tours. Programming at Ottawa National Wildlife Refuge is designed around environmental education that focuses on instilling a public understanding and appreciation of these wetlands and the animal and plant species that populate them.

Additional Resources

Great Black Swamp Woods & Wanders: Nature’s Jewels in Northwest Ohio, Jim Mollenkopf.

The Late, Great Lakes: An Environmental History, William Ashworth.