Alaska is mostly too far north and outside of mountain lion distribution. As such, there isn't much of a resident population aside from a few cats that live in the southeastern edge of the state adjacent to populations living in British Columbia.
Climate change may be increasing the habitat available to mountain lions, only time will tell.
There have been other reported sightings over the years, but there are only two documented accounts of mountain lions being killed in Alaska in modern times. The first was in 1989 when a mountain lion was shot near Wrangell. The second was in 1998 when a wolf trapper reportedly snared a mountain lion on South Kupreanof Island.
It is likely that some reported sightings are lynx or other animals. Lynx are found throughout the state and could easily be mistake for mountain lions.