A rare event turns the Grand Canyon into Cloud City

Over the weekend, rare atmospheric conditions gave rise to an even rarer scene: The Grand Canyon – that vast, gaping wonder of the natural world – filled to the brim with cold, dense, roiling fog. National Park officials have called the sight a "once in a lifetime" event. Looking at these photos, it's not hard to see… » 12/02/13 12:16pm 12/02/13 12:16pm