Crater Lake
Crater Lake National Park, Oregon
Crater Lake has snowstorms from September to mid-June, which helps explain how an old volcano crater became filled with water. It's the deepest lake in the U.S. -- or the Western Hemisphere, depending on how you measure it -- and arguably the bluest and cleanest as well. Also famous for the "Old Man of the Lake," a tree stump that's been bobbing in the ultra-pure water since at least 1896.