I briefly stopped by Westmoreland Park in Portland this afternoon and found this female-type Eurasian Wigeon. I only stayed for a few minutes, so the following images are all I got (and there are no wing pictures):
The head is richly brown, darker than the breast and flanks. This brown head is in stark contrast to the American females around it. This shot shows the steep forehead (compared to a more gentle stop for American) and the bill is not showing the black outline around the base (which Americans always show).
The following 2 hots, albeit being pretty bad, show the contrast and the coloration of the bird in comparison with the Americans.
The following article helps to id the female-type Eurasian Wigeon in the field: http://www.apw.aba.org/birding/v37n2p156.pdf.
Another shot from 02/13: