Alaska missing a lot of areas/buildings?

[chris]

In looking at the latest data for Alaska (the 2020/downloaded the Alaska data in the last 6 months), it seems it only covers part of the state. For example, if I import all the Alaska buildings into PostGIS, and then do an ST_ConvexHull to get a bounding polygon (see query below for reference) for where these are, I see this:

Yet, I see there are buildings in places like Nome and Dillingham (where the two arrows are), as well as many others. I've queried for buildings in these areas and don't find them. Am I missing something? Or is the Alaska data less complete, or?

Bounding polygon query I used (note that I have added a state column in my DB, and set it to the particular state when importing each state):

SELECT st_asgeojson(ST_ConvexHull(ST_Collect(wkb_geometry))) AS ak_bound FROM buildings_usa WHERE state = 'Alaska';