Both male and female are camouflaged with patterns of brown, gray, white, and black. Males have dark gray tails and paler gray underparts. In display, males reveal yellowish air sacs on the neck, and their eye combs swell and become a rich yellow-orange.
Sooty Grouse spend much of the day resting and feeding. They forage on the ground for plants and insects, as well as in trees where they take leaves, needles, and buds, especially in winter. Males display in early spring from perches in trees, making short flights and performing strutting displays on the ground.
Mountain and coastal coniferous forests (hemlock, fir, Douglas-fir, pine), mostly where there are openings, as well as subalpine forests, especially ones with extensive grass and shrub understory.
Ornithologists recognize four subspecies, which differ mostly in the shape of their tail feathers and the pattern on those feathers. In the northernmost,sitkensis, of Alaska and British Columbia, males have a narrow gray tail band and females are rather rusty above. In fuliginosus, found on coastal slopes of British Colombia to California, females are much grayer above.On the eastern slopes of the coastal mountain ranges, from Washington to Nevada, subspecies sierrae has a broad gray tail band. And from Fresno County south to Kern County, California, the similar howardi has an even broader tail band and longer tail. The northern subspecies tend to be darker (especially males) than the southern.