Alaska Airlines has round-trip flights from Dallas (DAL/DFW) to Seattle (SEA), Portland (PDX), or San Jose (SJC) starting at $177, NONSTOP. $89-$99 each-way. Flights April to May, on Tuesdays, Wednesdays, and Saturdays. Friday departures available for +$20 to +$40 more. Origin/Destination reversible.
Expect prices to fluctuate by +/- $20.