The Dusky Grouse is endemic to mountainous regions of interior western North America from central Yukon south to northern Arizona and New Mexico (Figure 1). Formerly considered the interior subspecies of the Blue Grouse, recent DNA evidence supported a split of the Blue Grouse into two species, the Dusky Grouse and the Sooty Grouse (see Systematics). The Dusky Grouse breeds in the continental shrub/steppe high desert and along the edges of open montane forests. The species overwinters in coniferous forest, where conifer needles comprise the main winter food. Its breeding distribution appears to be partly determined by the proximity of montane forest that is appropriate for use in winter. The Dusky Grouse shares physical and behavioral attributes with both ‘forest' and ‘prairie' grouse in the subfamily Tetraoninae.
Data from the North American Breeding Bird Survey (BBS) suggest that from 1968–2015, Dusky Grouse populations increased 1.7% per year for the survey-wide region (1). Occupation of relatively inaccessible montane forests during much of the year may contribute to a generally healthy population status in many areas. However, this result should be viewed with caution given the low detection rates on the BBS.