Purple Martins are the largest North American swallow. They look for natural cavities to live in such as wood pecker holes, cliff faces, and other such.
Purple Martins are classified as Casual (Not annual; these species are beyond the periphery of annual range, but recur in Alaska at irregular intervals,) species in Alaska by the University of Alaska. The subspecies Progne subis arboricola makes it way to Alaska.
Alaska Maritime Refuge has the Purple Martin listed as occurs in Bering Sea Unit unit (non-breeder).They are classified as an accidental species in Seward meaning not regular but not out of the question either.