I’m not sure about Tucson, but the routes out of DEN are probably only seasonal help for the holidays unfortunately, especially since the MAX is grounded.

I don’t see YX consistently flying out west without a closer base established. With SDF opening again and BOS starting to take flight, another base in the near future is unlikely. They’ll have too much on their plate trying to make sure they perform for DL out of BOS right now. Now I would like to think that if YX performs really well with these western routes, UA might take notice, BUT we’re talking about United. AA and DL are the only ones that seem to award more flying to top performers.