Darby has a lot of Blue grouse. I'm from the Bitterroot and used to take 50 or so mountain grouse a year in that country.
I hate to endorse road hunting, but if you straight up want to kill grouse, just drive the Forest Service roads in the mornings or dusk. They're quite often on the roads getting grit. The blues are quite often in the more open beargrass or sage covered areas, spruce grouse are normally in the dark timber and ruffed can be anywhere, but are quite often in the riparian areas by creeks.
The spruce grouse are as dumb as piddler, the blues are somewhat smarter and the ruffed quite often will flush before you even see them.
Good luck. You'll get into them pretty easily.
