Pasco should do better in 2019.
Got curious and looked it up... PSC was up big in January (12%). UA expansion was part of it... but it appears this was mostly due to Alaska returning to a higher level of flights as they had in '17.
Was this due to Horizon resolving their severe pilot shortage issue and they were able to resume some flights to SEA?
Most likely, yes. Also, for the first 2 months of '17, we had really bad weather (snow, ice) in the PSC area that started in mid-December '16 and ended in early March '17, so a lot of flights were cancelled back then. AS is back to their 4-5 flights a day to SEA. Last winter was mild, and then last month was bad with some delays and cancellations, but not as bad as 2 years ago.
UA also added another flight to DEN as well, and DL added a second daily to MSP.
Not too much longer, DL and UA will be the big carriers, with AS getting passed by. Allegiant is now all A320, though I don't know what their commitment to here is, really. I'd love to see DL start PSC-LAS, which would effectively end Allegiant's presence here, but that would impact PSC-SLC, however. Very strong DL customer base in this region, which started with Western Airlines.