YVR—Cannot List on Skywest—Why?

I flew from SAN to YVR and was able to list on a Skywest flight. I am a Delta employee. Anyway, I was looking at return flights, and there are many Skywest flights out of Vancouver, yet I cannot list on them as they are “greyed” out on the list. Do you know why? And, more importantly, what is the best way to get home? Should I try to get a automobile ride to SEA, and then, non-rev from SEA-San? Please advise.