| Allen |
| Kendrick Woods State Nature Preserve |
|
| Auglaize |
| Grand Lake St. Mary's State Park |
| Grand Lake St. Mary's Wildlife Area |
| Lake Loramie State Park |
| Memorial Covered Bridge |
|
| Champaign |
| Cedar Bog State Nature Preserve |
| Davey Woods State Nature Preserve |
| Kiser Lake Wetlands State Nature Preserve |
| Kiser Lake Wildlife Area |
|
| Crawford |
| Carmean Woods State Nature Preserve |
| Sears (Paul B) Woods State Nature Preserve |
|
| Defiance |
| Independence Dam State Park |
| Oxbow Wildlife Area |
|
| Delaware |
| Alum Creek State Park |
| Chambers Road Covered Bridge |
| Delaware State Park & Wildlife Area |
| Earthquake Information Center - Displays relating to earthquakes, |
|
including a near-real-time display of ground motion |
| Hutchins (Highbanks) State Nature Preserve |
| Olentangy Indian Caverns $ |
| O'Shaughnessy Reservoir and Dam |
| Seymour Woods State Nature Preserve |
|
| Fulton |
| Goll Woods State Nature Preserve |
| Harrison Lake State Park |
| Maumee State Forest |
|
| Hancock |
| Van Buren State Park |
|
| Henry |
| Independence Dam State Park |
| Mary Jane Thurston State Park |
| Maumee State Forest |
|
| Logan |
| Bickham Covered Bridge |
| Campbell Hill |
| Indian Lake State Park & Wildlife Area+A43 |
| McColly Covered Bridge |
| Zane Shawnee Caverns $ |
|
| Lucas |
| Audubon Islands State Nature Preserve |
| Crane Creek State Park |
| Irwin Prairie State Nature Preserve |
| Kitty Todd State Nature Preserve |
| Maumee Bay State Park |
| Maumee State Forest |
| Oak Openings Preserve |
|
| Mercer |
| Grand Lake St. Mary's State Park |
| Mercer Waterfowl Area |
|
| Morrow |
| Mt. Gilead State Park |
|
| Ottawa |
| Catawba Island State Park |
| Crane Creek State Park |
| Crystal Cave/Heineman Winery $ |
| East Harbor State Park |
| Lakeside Daisy (Colleen "Casey" Taylor & Ruth E Fiscus)
State Nature Preserve |
| Magee Marsh Wildlife Area |
| Marblehead Lighthouse State Park |
| Maumee Bay State Park |
| Metzger Marsh Wildlife Area |
| Middle Bass Island State Park |
| Needle's Eye Sea Arch (Put-in-Bay Harbor-South Bass Island) |
| Oak Point State Park |
| Perry's Cave $ |
| Portage River (Lake Erie Access) Wildlife Area |
| South Bass Island State Park |
| Sportmen's Migratory Bird Center |
|
| Sandusky |
| Mull Road Covered Bridge |
| Miller Blue Hole |
| Pickerel Creek Wildlife Area |
| Resthaven Pond & Wildlife Area |
|
| Seneca |
| Collier (Howard) State Nature Preserve |
| Seneca Caverns $ |
| Springville Marsh State Nature Preserve |
|
| Shelby |
| Gross (Samuel) Memorial Woods State Nature Preserve |
| Lake Loramie State Park |
|
| Union |
| Bigelow/Little Covered Bridge |
| Culbertson/Treacle Creek Covered Bridge |
| Milford Center Prairie State Nature Preserve |
| Spain Creek Covered Bridge |
| Upper Darby/Pottersburg Covered Bridge |
|
| Williams |
| La Su An Wildlife Area |
| Lockport Covered Bridge |
|
| Wood |
| Ostego Park |
| Steidtman Wildlife Santuary |
|
| Wyandot |
| Indian Trail Caverns $ |
| Killdeer Reservoir Wildlife Area |
| Parker Covered Bridge |
|
Swartz Covered Bridge |
|
