It might help to go by a process of elimination first. For instance, Genie, the bird you are describing is definitely not a Ream-Nosed Romflombeler. Nor is it a Tippling's Twaddler, a Maleficent Gulch, a Parsimonious Nuthatch or a Least Western Glebe. Though it does appear to have some features in common with the Peckerson's Glebe, that bird's range would not likely place it in Portland, Oregon at this season, so I think we can cross the PG off the list too.