Lost Lake is named thus because at the bottom of the lake is a 6-foot diameter lava tube that constantly drains the lake. In the fall and winter, the water flows in faster than it flows out. In the late spring/early summer, however, the water flowing in slows enough that the lake drains to little more than a shallow marsh. This TB definitely has seen some cool places, including this lake. I'll try to keep it moving to similarly cool places.
For more information on Oregon's amazing disappearing lake, you should check out:
http://www.dogonews.com/2015/5/23/why-oregons-lost-lake-disappears-every-year