Doesn't that schedule allow for full crew rest without remaining on duty, so the crew can work a full day finishing with PDX-RDM, overnight in RDM, and then work a full day starting with the RDM-PDX flight? So I wonder if it's for those operational reasons? Otherwise it is a bit weird to see a flight from an aircraft that overnighted leaving after 7 AM.

(Pretty sure a crew could just do the PDX-RDM-PDX with a 6-8 hour overnight and remain on duty overnight, but then they pretty much couldn't fly anything else on the day of the PDX-RDM or the RDM-PDX flight.)