Adak was hit really hard by a jack*** outfitter a couple years ago....took nearly every mature, and almost mature bull off....but, if I were looking for more info on alaskan hunting in general I would look through the archives at
www.forums.outdoorsdirectory.com there are several threads detailing caribou hunting on Adak. Also send a message to Michael Strahan on that board, he has alot of insider knowledge on that subject.
Good luck.