I did some research but I want confirmation because I'm really not sure. I live in northwest Oregon and I found it growing nearby our barn, on the ground underneath the eave of the roof.
This is known as a cup fungus (Peziza phyllogena) which commonly grows on decaying logs. The cup shape is distinctive, and the presence of the log helps confirm this. It can also grow on wood chips. Read the wiki article carefully to compare with your fungus.