Travel from June 29 - July 6, or from August 30 - September 4.
I found flights for a quick trip over 4th of July, departing Seattle SEA on an evening flight Wednesday, July 3, returning from Portland PDX on an afternoon flight Friday, July 5.
I also found flights for a trip on peak travel days over Labor Day weekend, departing Portland PDX on Friday evening, August 30, returning from Seattle SEA on Monday evening, September 2.
This fare includes a carry-on bag plus one personal item. A checked bag costs $30 each way.
On Delta's Basic Economy fare, seats will be assigned at random upon check-in for this price. Alaska Airlines has limited seat selection in the back of the plane.
Main Cabin Economy fares are only $20 more roundtrip, which comes to $117. This will include standard advanced seat assignments and allow ticket changes/upgrades for a fee. A checked bag costs the same $30 each way.
If you're willing to pay a little extra, for $125 roundtrip you can book a seat in Delta's Premium Economy (Comfort +) cabin. You'll get up to 4" of extra legroom, dedicated overhead bin space, and early boarding.
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