Yes, it is a beautiful part of Maryland. Both the State and National Park are very nice. There is a large man-made lake for swimming (and canoe training) at Cunningham Falls State Park. Might see a Copperhead or a Timber Rattler (two poisonous snakes) and maybe a black bear. But there aren't many. Camp David (the US Presidents Rural Retreat) is actually within the confines of Catoctin Mountain National Park.
By mountain climber standards Catoctin is a good-sized hill. There used to be a few sites for rock climbing.
There are some informational exhibits on "moonshine" and "charcoal making."
All of the information above is spot on. If a person has any interest in America's Civil War, Gettysburg and Antietam Battlefield tours should not be missed. Gettysburg (the town) is quite a civil war tourist trap, but the battlefield is of great interest. Antietam is much more laid back and rural with very little glam and glitter.
My family and I spend many hours and nights in both of these parks when the kids were younger.
Roger in Baltimore