Where Is Fernwood?

Vintage TV fans remember that both "Mary Hartman, Mary Hartman" and "Fernwood 2-Night" were set in fictional Fernwood, OH. According to the companion book "Fernwood, U.S.A." ("text and direction by Ben Stein"), Fernwood was first discovered by the Lewis and Clark Expedition.
"The intrepid explorters had left the confluence of the Monongahela and Allegheny rivers, later to become Pittsburgh, and were advancing through the dense marshes and forests of what became Ohio," the book says. "Indian guides had spoken of a clearing in the forest where the sun's light was miraculously clear and bright. By sheer luck, Lewis and Clark found that place.
"They made camp there, and sent out men to find appropriate places for the necessary acts of men trekking through the woods. ... Those men came upon an area lushly full of ferns of all kinds, not to mention dense woods to ensure privacy.
"The spot where the sun so beautifully shone has been lost in the mists of history, but the spot where the ferns and woods grew so thick became our town."