The Alaskan growing season simply isn't long enough to support many fruits and vegetables, so the traditional diet was pretty heavy on meat and seafood. In order to get enough vitamins and nutrients, every edible part of the animal was used in food preparation. Russian immigrants and gold-rush prospectors started introducing other foods, particularly grains and legumes that could be transported over long distances and preserved.
Eggs, particularly from sea birds
Anything else to add?