John Waller, a fly-fisherman fighting stage 4 cancer, took to the waters of Crater Lake in search of trout that have been growing rapidly in size.

Host Zach Urness and outdoors intern Mariah Johnston talk about hiking, camping, and how to access Crater Lake's water for ...

In the late 1800s, fish were introduced to Crater Lake to attract visitors. In 1915, park managers introduced signal crayfish as a food source for the fish, according to park history.