09/04/2026
Ohio has a continental divide running across it, and almost nobody driving over it has any idea.
It is not the Rocky Mountain divide. This is the St. Lawrence Divide, sometimes called the Eastern Continental Divide's northern branch, separating water that flows north into the Great Lakes from water that flows south into the Ohio River and eventually the Gulf of Mexico.
The line runs roughly west to east across the northern third of the state. It comes in near the Indiana border around Mercer and Auglaize counties, tracks northeast through Hardin, Wyandot, Crawford and Richland, then continues east through Ashland, Wayne, Summit, Portage and Geauga toward Pennsylvania.
North of it, water goes to Lake Erie through the Maumee, the Sandusky, the Cuyahoga and the Grand, then out the St. Lawrence to the Atlantic. South of it, water goes to the Scioto, the Muskingum, the Great Miami and the Hocking, into the Ohio, into the Mississippi, and out at New Orleans.
Two raindrops falling a few feet apart in Hardin County end up 1,800 miles apart.
The reason the divide is so unremarkable to look at is that the elevation change is almost nothing. This is glacial terrain, flattened and filled, and in places the divide is a barely perceptible rise in a soybean field. Portage County got its name from the portage between the Cuyahoga and the Tuscarawas, a short carry across the divide that Native peoples and later traders used for centuries.
That portage is also why the Ohio and Erie Canal ran where it did. Akron sits near the summit, and the canal needed a huge flight of locks to climb over the divide.
A few small markers exist. Most people cross it on I-71 without slowing down.
