During periods of heavy snowfall and accumulation, ruffed grouse will often gather in dense rhododendron and laurel copses. Of course, this can be a difficult time to hunt birds, for both human and canine, but some fetching wingshooting action can take place. Grouse have been known to even dive into heavy snowfall in order to survive low temperatures. The birds have also been known to remain there until weather conditions improve. Snow, of course, has insulating qualities.
Another way to gain information on where to find birds is to examine their crops. For example, every grouse and turkey that I am fortunate enough to kill, I always examine their crops after I have finished removing all meat from the carcass. The crops can supply a wealth of information on where a bird is spending its time and what it has been consuming. I have friends who call me when they down a bird, and I do the same for them. Between us we can share what we have found in various birds' crops.
One time while a friend and I were grouse hunting in the Jefferson National Forest back some years ago, we made one swing through a particular birdy thicket and put up several birds. We then turned around and made another pass, flushing what we thought were certainly two different birds. The two of us even briefly considered making a third pass before we eventually decided to move one ridge over and hit that locale.
Today, we would likely have only run through that particular place one time, and then embarked in a vehicle to some other place on public or private land for a quick pass. And next, we would have been off to another spot, maybe even in a different county. That's grouse hunting today for many people in many parts of the Mountain State.