The surface of the department consists of undulating and well-wooded plains, intersected by numerous valleys, and diversified in the north-east by hilly ground which forms a part of the mountain system of the Ardennes.
The surface is a slightly undulating plain.
The river banks, however, are fringed with trees, and in the more undulating lands the timber belts vary from a few hundreds of yards to 5 or 10 m.
Although in many districts there are low ranges of hills, the surface is more often a desolate and monotonous plain, flat or slightly undulating.
The Park consists of about 265 acres of undulating land with natural woods and rocks, traversed by a gorge cut by Rock Creek, a tributary of the Potomac. The river and gorge extend into the country far beyond the Park, and in addition to the animals that have been introduced, there are many wild creatures living in their native freedom, such as musk rats in the creek, grey squirrels, crested cardinals and turkey buzzards.