Volcanic Activity and the formation of the lake itself make this lake the deepest lake in the United States with a depth of 1,943 feet making it also the deepest volcanic lake in the WORLD!
The eruption from Mount Mazama was a highly explosive eruption blowing pyroclastic felsic material in the air and creating a crack around the mountain allowing it to then collapse in on itself. The pyroclastic material can be found in all different places in the world like in some of the ice in Greenland. The last eruption being around 7,700 and lasting a few days.
Crater lake is a dormant volcano! This means that the volcano will one day wake up and restarting the volcano cycle. The volcano has been inactive for about 5,000 years so it is nothing to worry about.
If this volcano suddenly became active it would cause a number of problems. some of these problems include the caldera wall collapsing causing issue in the lake. This could also lead to earthquakes and possible land slides in the area around the base of the mountain\=]''[=