Every city has an environmental story, perhaps none so dramatic as Pittsburgh's. Founded in a river valley blessed with enormous resources-three strong waterways, abundant forests, rich seams of coal-the city experienced a century of exploitation and industrialization that degraded and obscured the natural environment to a horrific degree. Pittsburgh came to be known as "the Smoky City," or, as James Parton famously declared in 1866, "hell with the lid taken off."

Then came the storied Renaissance in the years following World War II, when the city's public and private elites, abetted...