Waldo Lake is the nation’s shining example of an ultraoligotrophic high-mountain lake. Say what? Ultraoligotrophic. Essentially, Waldo Lake has extremely clear and pure waters because its watershed is so small (roughly twice the area of the lake) and clean; the healthy forest delivers relatively few organic materials or nutrients. In fact, the waters of Waldo Lake are so clear it that they set the world-record for depth of visibility at 157 feet.