Seattle to Anchorage, Alaska is priced at $78.24 each way for travel most dates in May or June with a fare war between Alaska Airlines, Delta and JetBlue for $156 round trip tickets. The price only rises to $101 each way for most July and August dates. Anchorage is like a low cost carrier ticket price these days from many west coast airports.
The departure and arrival times of these flights kind of suck with midnight arrivals in Anchorage and 6am arrivals in Seattle.
These same low fares are also available for Portland PDX flights to Anchorage.
Here are the number of dates each month with low $78 one-way fares:
May 2016 SEA-ANC; ANC-SEA low $78 one-way fares
Alaska Airlines = 19 dates; 12 dates
Delta Airlines = 18 dates; 17 dates (other dates $97)
JetBlue = 28 dates; 26 dates
June 2016 SEA-ANC; ANC-SEA low $78 one-way fares
Alaska Airlines = 0 dates ($142 low fare); 17 dates
Delta Airlines = 19 dates; 27 dates
JetBlue = 18 dates; 30 dates
July 2016 SEA-ANC; ANC-SEA low $101 one-way fares
Alaska Airlines = 18 dates; 11 dates
Delta Airlines = 25 dates; 22 dates
JetBlue = 14 dates; 14 dates
August 2016 SEA-ANC; ANC-SEA low $101 one-way fares
Alaska Airlines = 31 dates; 25 dates
Delta Airlines = 31 dates; 27 dates
JetBlue = 30 dates; 27 dates
I show the one-way fares since you may need to fly two different carriers to get the exact dates you want for lowest round trip fare.
Delta Air Lines Seattle SEA – Anchorage ANC
$156.48 Monday June 20 – Sunday June 26
Alaska Airlines Seattle SEA – Anchorage ANC
$202.50 Thursday July 21 – Monday August 1
Alaska Airlines Economy R code is not a miles earning fare for AAdvantage flyers as of Jan 1, 2016.