crater lake is known for its famous piece of driftwood, named the "old man of the lake". it is a tree that has been moving up and down in the water for more than 100 years. the lake water is cold, so the tree is well preserved. originally, fish did not live in the lake. however, people stocked the lake with different kinds of fish between 1888 and 1941. several species of fish still live in the lake.