Southwest Airlines route map, January 1996 | The Southwest A… | Flickr
Southwest Airlines Announces Four New Nonstop Destinations at OAK - Oakland International Airport
Southwest set to open int'l concourse at Houston Hobby: Travel Weekly
Open-source airline route maps from 1999 and 2018 created using Python and BTS data (see corresponding comment for clarifications + GitHub link) [OC] : r/dataisbeautiful
Airline Maps on Tumblr
Airline Insight: Southwest Airlines | Corporate Travel Community