The Cleanest Cities in the U.S.

Maybe it makes sense that Clearlake — a bucolic town in northern California — has one of the few school boards in the U.S. with a Green Party member. The air in this community of 15,000 people is about as pure as it gets in the U.S. — and stands in stark contrast to the smog valley of southern California. Ironically, the actual Clear Lake itself is heavily contaminated with mercury, thanks to a nearby abandoned mine. But I guess you can't have everything.

See the 10 most air-polluted cities in the U.S.