 There was also a big seasonal imbalance in travel to Alaska , which mainly took place in the summer . In an effort to compensate for this , the airline introduced service to Mexican resorts , where most travel takes place in the winter . In 1988 , the airline began servicing the Mexican resort cities of Mazatlan and Puerto Vallarta . By the end of the 1980s , 70 percent of Alaska Airlines ' passengers flew south of Seattle and the airline served 30 cities in six states outside Alaska . The airline had successfully used the state of Alaska as a springboard to expand into larger , more profitable markets . 
