| Nonstop Flights: San Antonio or Austin to/from Denver $97 r/t [September-December] â United United has round-trip flights from San Antonio or Austin (SAT/AUS) to Denver (DEN) for $97, NONSTOP. Flights September to December. Weekends available. Origin/Destination reversible. Change fees are waived, but Unitedâs âBasic Economyâ fares do not include a free carry-on bag. Only a personal item (like a small laptop bag) is free. Seats are randomly assigned for free prior to boarding. If you have the United MileagePlus credit-card, use the âfree checked bagâ perk. The personal item size on United flights is smaller (9-in/10-in/17-in) than Frontier or Spirit (8-in/14-in/18-in). Want a notification sent straight to your phone when any new deals are found? Join our Telegram channel and never miss another deal. Patreon supporters receive a recap of all the airfare deals currently available from Austin and San Antonio everyday. We donât charge a subscription fee. Our deal notifications are available for FREE via Instagram, Facebook, Twitter, Telegram, our Webpage, and our E-mail list. If you are paying someone a subscription fee for this content, you are being ripped off. Click for more details and booking links Nonstop Flights: San Antonio or Austin to/from Denver $97 r/t [September-December] â United . | 