Top three images - 2005. A good reason to keep a dead tree in your yard. It made this hole, hung around for weeks and then left.
It had fierce battles with starlings over the hole. They would lock together and drop to the ground.
The first photo appeared in an article about Oklahoma woodpeckers in the 2007 Nov/Dec issue of Outdoor Oklahoma magazine
and the Winter issue of The Wild Side newsletter, both issued by the Oklahoma Department of Wildlife Conservation.
Second row: 2008 - First one seen here since 2005.
Reference: RHWO
2012 - Juvenile hanging around in mid October. It appears to be storing small acorns in the dead tree. I will try to follow its color change into the Spring.