Here is the best account of the battle plans and invasion of the Aleutians, complete with photos, that I have read. The Japanese were actually there from from early June 1942 to late August 1943.
Aside: Alaska is BIG. Attu, the most westerly settlement on the Aleutian Chain, is 1200 miles from Anchorage on the mainland. Across the water to the northeast is Juneau 1900 miles away.