Hi Bob. I think that your bird is a Sooty Grouse. A young male maybe. FYI, Sooty and Dusky Grouse were split from Blue Grouse, Sooty being the coastal species.
I'll give it a shot John! I think this is a "blue" type grouse because of the combination of the dark gray head, neck and breast, lack of a "ruff" in the lower neck area, white terminal tail band and throat markings. Then, assuming that the location this photo was taken is Belfair WA state, this tells me that this "should be" a Sooty Grouse and not a Dusky Grouse if we can believe that the orniths that split the Blue Grouse were accurate about ranges. Lastly, from my experiences with this species, the "jizz" says Sooty Grouse to me.