The Sooty Grouse is endemic to mountainous regions in western North America from south-coastal Alaska and northwestern British Columbia south to the Sierra Nevada Mountains in California and westernmost Nevada (Figure 1). Formerly considered the coastal subspecies of the Blue Grouse, recent DNA evidence supported a split of the Blue Grouse into two species, the Sooty Grouse and the Dusky Grouse. The Sooty Grouse occupies a range of breeding habitats from coastal rain forest to subalpine/alpine forest. Virtually all populations overwinter in conifer 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 Sooty Grouse shares physical and behavioral attributes with both ‘forest' and ‘prairie' grouse in the subfamily Tetraoninae.
Sooty Grouse can attain high population densities and remains distributed throughout most of its historic range. Even so, data from the North American Breeding Bird Survey suggest that the survey-wide population decreased by 1.8% per year from 1968–2015 (1), although detection rates are low and results should be viewed with caution. Additional information is needed on population numbers and trends.