She has done the research so you and I don't have to. She actually has a list of 7 of the best U-cut , so make sure you click on her link above.
McMurtrey's Red-Wood Christmas Tree Farm between Redmond and Woodinville
Carnation Tree Farm in...Carnation.
Oh, just go to Callie's site - it's so much better. Why do I bother?
Here's some pretty pictures: