Alaska Airlines made a sweeping fare simplification and rationalisation that tightened the spread between high- and low-end fares, and also reduced first class and coach fares, eliminated maximum-stay rules and fare surcharges, and reduced the number of fare categories in each market. The fares are available in most of its routes in the Pacific northwest, California and Alaska, the routes on which Alaska faces its strongest low-fares competition from Southwest Airlines.
Source: Airline Business