Originally Posted by tatterdema

They are winter only. No one fly's non stop between SEA and PVR or CUN after the end of May. You should be able to find March on both Alaska and Delta, and April up until at least April 20th. I know Alaska flys non stop to PVR until at least May 18, because I am booked for then, but coming home the last week of May I had to book a connecting flight.