The Dark-eyed Junco (Gray-headed) breeds in northern Nevada, Utah, and Colorado and winters in southern Utah, Colorado, Arizona, and New Mexico (Sibley 2014). In Montana, individuals of the Gray-headed population of Dark-eyed Juncos have a couple of records over the past decade.
For a comprehensive review of the conservation status, habitat use, and ecology of this and other Montana bird species, please see Marks et al. 2016, Birds of Montana.
Direct Evidence of Breeding
Indirect Evidence of Breeding