I checked this when planning a trip to Oregon, and yes—Southwest does fly to Eugene. I almost missed it because I was comparing prices and accidentally filtered U.S. west-coast routes out. What helped was going straight to their site, where you can instantly see every available city and modify your booking on the spot. I actually had to cancel my first reservation after my dates changed, and the credit applied instantly, which made rebooking really simple. If you’re thinking about Eugene, that’s the easiest way to check your options.