This dark-backed woodpecker was near Rist Canyon pass. The dark back and large bill and gray (not white) tuft at the base of the bill suggests Black-backed Woodpecker (undocumented in Colorado but resident in Black Hills of southwest South Dakota). The head pattern (broad white eye-stripe) and lack of barred flanks is typical of Hairy Woodpecker. The number of toes is not clear in the photos. The gray smudge on underparts suggests melanism. Local experts favor an odd Hairy, perhaps darkened due to melanism or char-stained.