Alaska tree frogs

Question
How does Alaska tree frogs survive the deep freeze of the Artic circle?

Answer
Curtis, I know of no such frog.  I do not believe any frogs go further north than the chorus frog which ranges into Canada.  Some frogs will literally freeze into suspended animation and then "come back to life" when the weather warms up.  But I've never heard of the Alaskan tree frog.  BPC