The Constitution Party typically does strong in the remote parts of Alaska, this year wasn't the only one. The reason might be that the Alaska Independence Party is pretty closely associated with it and basically serves as its de facto state affiliate (it used to be official in the past), and the AIP actually has some influence and a machine in those areas.
The Alaska CP platform contains some Alaska-specific items that aren't necessarily right-wing that I think broadens their appeal.
Lewis also mentioned something about Yup'ik evangelicals being CP/Dem swing voters.