Looks similar but is much larger (around 9 inches) than it's smaller version, the diminutive (around 6 inches) downy. An early lesson in my birdwatching: "Huge Hairy, diminutive Downy".
Spring brings the Hairy woodpecker pairs out, chasing each other in spirals around the Douglas fir. As the young grow into their adult plumage, you can still see the adults feeding them from time to time.