I'm thinking this is a Taxus brevifolia, otherwise known as a "Western Yew". They're most commonly found in the northwest region of the United States; so, even if the tree was planted, it's quite probable that it was still acquired (somewhat) locally.
I had a difficult time finding an image that so directly matches the bark image you provide, just from where that tree is so young, but I was able to find a matured version of the tree, which still has a similiar color and bark pattern. I believe that when the tree matures, the vien-like bark sheds, which results in the "scarring" that can be seen in the following image.
And then here's a few images that show the foliage. Notice the similarities in how the pines flare out, and the coloration of the branches. Once your tree matures, it'll get darker in color and develop small red berries, as can be seen in the following images.
The mature tree is on the left, and the right is still developing (which is most accurate to your images).
There is a small chance that the species provided by this answer is inaccurate, but I'm sure it's at least within the Taxaceae family.