Crater Lake National Park in Oregon

 
Crater Lake, famous for its deep blue color and pure water, was formed after the volcanic eruption of Mount Mazama some 7,000 years ago.  With a depth of 1,943 feet, Crater Lake is the deepest lake in the United States, and the seventh deepest lake in the world. In June of 1853, John Wesley Hillman was believed to be the first person of European descent to see what he named the “Deep Blue Lake” in Oregon. At an elevation of more than 7,000 feet above sea level, Crater Lake averages about 44 feet of snow annually.  Its fresh water is considered some of the purest water found anywhere in the world.