I've been finding the fresh work of a pileated woodpecker, Dryocopus pileatus, in the back of the property. We know we have a few around as we can hear them sometimes. We also had the pleasure of watching from our front porch a few summers ago as a pair feasted on blackberries. I captured a few fuzzy photos - look for red head and stripes.
Pileated also make some of the largest oblong tree holes in their search for insects. There are two in the picture above of the red maple on our property. The newer, smaller one is about 6-8" high and the tree sap is pouring out down the tree trunk (wish we could tap that!).
If you've never seen one (they are shy birds), pileated are large and can reach up to 20". In comparison, the more common woodpeckers that arrive at a feeder, downy and hairy, are 6.5 to 9.5" respectively. Check out Audubon's info page for other interesting pileated facts.
You can't mistake a pileated call!