I've found lots of them over the years on the Mt. Hood National Forest (Clackamas River Ranger District and Zigzag Ranger District). Just a week ago I found a grapefruit sized one not far from Clear Lake. I saw one years ago that was over 2' in diameter. They aren't as numerous as many other mushrooms; it seems like I've stumbled across them randomly, whereas I can usually predict the type of forest where I can find chantrelles.
I've heard that they are really good to eat but every one I've found, even the fresh small ones, had worms in them.

So I stick to chantrelles.