 crater lake national park is a united states national park located in southern oregon. established in 1902, crater lake national park is the fifth oldest national park in the united states and the only one in the state of oregon. the park encompasses the caldera of crater lake, a remnant of a destroyed volcano, mount mazama, and the surrounding hills and forests. the lake is  deep at its deepest point, which makes it the deepest lake in the united states, the second deepest in north america and the ninth deepest in the world. crater lake is often referred to as the seventh deepest lake in the world, but this former listing excludes the approximately  depth of subglacial lake vostok in antarctica, which resides under nearly  of ice, and the recent report of a  maximum depth for lake o'higgins/san martin, located on the border of chile and argentina. however, when comparing its average depth of  to the average depth of other deep lakes, crater lake becomes the deepest in the western hemisphere and the third deepest in the world. the impressive average depth of this volcanic lake is due to the nearly symmetrical  deep caldera formed 7,700 years ago during the violent climactic eruptions and subsequent collapse of mount mazama and the relatively moist climate that is typical of the crest of the cascade range. the caldera rim ranges in elevation from . the united states geological survey benchmarked elevation of the lake surface itself is . this national park encompasses . crater lake has no streams flowing into or out of it. all water that enters the lake is eventually lost from evaporation or subsurface seepage. the lake's water commonly has a striking blue hue, and the lake is 
1902_establishments_in_Oregon Civilian_Conservation_Corps_in_Oregon Crater_Lake Crater_Lake_National_Park IUCN_Category_II Parks_in_Douglas_County,_Oregon Parks_in_Klamath_County,_Oregon Protected_areas_established_in_1902