Do Alaska boroughs/census areas have "seats"?
The boroughs do. The census areas don't.
As noted above, the outlying communities in the North Slope Borough (most notably Deadhorse/Prudhoe Bay) have no normal road access to the county seat in Utqiaġvik (formerly Barrow). There is regularly scheduled air service to Utqiaġvik, including Alaska Airlines 737 jets from Deadhorse and Anchorage.
Another unusual situation is the Lake and Peninsula Borough, whose communities have no road links to each other, or the borough seat in King Salmon, which is in the Bristol Bay Borough rather than in Lake and Peninsula. (Bristol Bay's seat is Naknek rather than King Salmon.) There is scheduled propjet air service between Lake and Peninsula communities and King Salmon, which has Alaska Airlines jet flights to Anchorage.
While the propjet flight routes are "scheduled", arrival and departure times aren't really. The flight I took from Chignik (on the ferry system) to King Salmon left two hours
early. A fishery office at the Chignik dock warned me that could happen, and was kind enough to drive me to the airport just before the plane arrived. The early departure may have been to accommodate a local mother and her baby, who had to fly back to the hospital in Dillingham (also outside Lake and Peninsula) for routine post-natal care, and got to show off her baby boy to friends and relatives scattered all over the Alaska Peninsula.
