On a cold and cloudy day, billowing steam from the giant 2,250 megawatt coal-fired Navajo Generating Station gives the impression that this otherwise pristine desert landscape just outside Arizona’s Glen Canyon Recreation Area is really an industrial wasteland. On a clear day, though, the steam and fog dissipate to reveal majestic red rock buttes and a yellowish band of smog drifting downwind from the plant as far as the eye can see.