Since Alaska was not explored for agates due to their low value, few Alaskan thundereggs have been brought to the market. I was able to obtain some from Mt. Talkeetna. Many are fractured due to deep freezing and thawing cycles as expected of Alaskan climate. I think it's possible to find more thunderegg beds around Mt. Talkeetna and on the northern side of the Alaska Range mountains along the south side of Alaska (Sublucation zone). The agates are generally colorless to white sometimes with hints of yellow and red.