A little west of Cumberland, MD on I-68 there's Rocky Gap, a Nicklaus course my father and I played a few years ago andquite enjoyed.
There are also a handful of respectable, mid-upscale public courses closer to Frederick, MD. My father and I liked Maryland National, and have heard decent things about the likes of Whiskey Creek and PB Dye Golf Club.
Near Westminster, MD (a bit NW of Baltimore...might be a bit out of the way depending on how you go) there's Piney Branch CC. I played it in a college tournament a couple years ago and recall it having some of the more interesting greens I've putted (both fast and undulating). It's private, but not impossible to get on, I'd imagine.
Also, I played in a junior tournament at Toftrees Resort in State College, PA and enjoyed that golf course.
Cheers.