Cuyahoga Valley

Declared in 2000, it protects the valley of the Cuyahoga river, so polluted by industrial discharge through much of the 20th century that its surface repeatedly caught fire, the blaze of 1969 — widely covered by the national media, though in fact less severe than several earlier ones — being one of the direct catalysts of the United States Clean Water Act of 1972. Today its recovered waters have allowed the return of the bald eagle and of dozens of fish species.