| Nonstop Flights: Austin or San Antonio to/from Denver $98 r/t [January-April.2021] â Southwest Southwest has round-trip flights from Austin or San Antonio (AUS/SAT) to Denver (DEN) for $98 with a connection. $49 each-way. Flights from January to April 2021. Origin/Destination reversible. Weekends available. Carry on bag is allowed for free and Southwest doesnât charge a change-fee. Want a notification sent straight to your phone when any new deals are found? Join our Telegram channel and never miss another deal. We send our Patreon supporters a daily recap of all fares in Austin that are near or below their 9-month moving averages. There were 173 fares in the latest report. If youâre interested in our analytical data, consider supporting our work on Patreon. Click for more details and booking links Nonstop Flights: Austin or San Antonio to/from Denver $98 r/t [January-April.2021] â Southwest . | 