"A huge, high mountain lake in a near-wilderness setting, Waldo Lake is unique. One of the largest, highest, deepest, and clearest lakes in the Northwest, Waldo Lake has no significant inlet streams. Instead, it is fed by precipitation and by underground springs whose naturally filtered water results in a crystal-clear, nearly sterile lake.
Due to the small volume of water that enters the lake each year, water is retained for an average of thirty-two years before it flows through the lake’s outlet. Due to the lack of nutrients, the lake supports few fish, and only two species of plants (both mosses) can be found on the lake’s floor."