• Wizard Island

    Crater Lake

    National Park Oregon

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  • Stage 1 Fire Restrictions in Effect

    To ensure public safety and to provide the highest degree of protection to park resources, restrictions on campfires, smoking, and fireworks are in effect. More »

  • Vehicle-Free Days on East Rim Drive

    The park will host two vehicle-free days on East Rim Drive, September 20 and 27, 2014. Although East Rim Drive will be closed for these events, all other roads through the park will remain open to vehicular traffic. More »

Are the Mazama Newts Poisonous?

Mazama and Oregon Newt

Mazama Newt from Crater Lake (left) and Rough-skinned Newt collected outside the park at Spruce Lake (right).


Both the Mazama Newt, and the more widely distributed rough-skinned newt, produce toxins as a defense against predation.

  • Newts are the only land animal to contain tetrodotoxin (TTX), an incredibly potent neurotoxin. Tetrodotoxin is also found in the deadly puffer fish and blue-ringed octopus.
  • Some newts can produce enough toxin to kill 17 humans.
  • Rough-skinned Newts from low elevations have 4000 times the toxin as Mazama Newts in Crater Lake.
  • The Mazama Newts found in Crater Lake are not very toxic compared to Oregon newts outside the lake.
newt toxicity bar graph

Toxicity levels for newts from four locations in the state of Oregon, USA.  Longer bars indicated higher toxicity levels.  Crater Lake newts are not very toxic compared to newts found in Soap Creek.


Why are the Mazama Newts not very poisonous?

Mazama Newts found their way to Crater Lake as early as 6000 years ago when there were no fish or crayfish predators. It takes valuable energy for the newts to produce the toxin and food resources for the newts in Crater Lake are scarce. The Mazama Newt may have lost its' toxicity due to the lack of predation and the general scarcity of food in Crater Lake .

Did You Know?

Did You Know?

Wizard Island is a cinder cone that erupted after Crater Lake began to fill with water. It is one of two islands in Crater Lake. Do you know the name of the other island?