Check out the Black Bear Tavern - I haven't been up to Deep Creek in probably four years or so, but used to go every summer for a week or two. I recall they had a number of beers on tap, but I'm not sure what its like now.
I know you're probably already there, so you've probably discovered McHenry Beverage Center. Not a brewery/brewpub, but they've got some really good stuff. Blackwater Brewing in WV is about 45 min away, IIRC.
Definitely hit up McHenry. Great selection there for such a small area. Mountain State BC has good food. Their brick oven pizzas are pretty great. The beer, however, is a bit underwhelming. Nothing offensive though, and they'll wash down your meal just fine.