North-facing slopes overlooking the Potomac offer some protection from the direct and drying rays of the sun, creating a cool microclimate for the Eastern Hemlock - Hardwood Forest. (Ecobit: How Topography Creates Microclimates)

The soil here is extremely acidic and infertile because the underlying bedrock does not contain a lot of calcium, magnesium or other elements that reduce the acidity of the soil and act as nutrients for plants.