Alaska Airlines doesn't list a limit for the number of checked bags per traveler. Each checked bag must weigh less than 50 pounds and have a maximum dimension of 62 linear inches to avoid additional charges, according to Alaska Airlines.
The standard fee for the first two bags under 50 pounds is $25 each, as of 2015. The third bag costs $75, as well as the fourth bag and more. Overweight or oversized bags are subject to an additional $75 fee per bag. In special circumstances, the baggage fee is waived. Checked bags cannot contain certain items including camping equipment, flammable liquids and pool chemicals.