Yep, Northern Flicker...and this one is a female, Yellow-shafted Northern Flicker [Eastern variety]. She has a gray crown with a red nape patch and yellow under her tail and wings. The males have a black malar.
The Red-shafted Northern Flicker [Western variety] have a brown crown and do not have a nape patch, they have red [more like rusty-orange] under their tails and wings. The males have a red malar. ?