We live NE Portland, 62nd Ave. Recently (Sept. 2016) these dropping have appeared in the back yard. They are about 5"-6" long, clustered in the same area, with a few clusters in different locations in the black yard. I have enclosed a photo of one piece. Thanks for your help.
Oh, great. Four years of college and now I must identify scat? Frankly, I do much better identifying bugs! (sigh)
So I was forced into an internet search using the phrase "identify scat" -- but without the quote marks.
The best match appears to be coyote. See the following links: (1) scat from the Rocky Mountains http://waynesword.palomar.edu/scat.htm; and (2) Wildlife Scat of Eastern Washington http://www.bentler.us/eastern-washington/animals/.