Sugarloaf Mountain is a privately-owned park that is open to the public, with an extensive network of trails. You can drive more than half way to the top, where there a great views of the area. Like the Bull Run Mountains, Sugarloaf Mountain is a monadnock — an isolated hill or small mountain of harder rock (metamorphic sandstones called quartzite) that has resisted erosion so that it rises abruptly from gently sloping or level surrounding land. It appears to be either an outlier of the main mass of the Catoctin Mountain to the west, or a root remnant of the ancient Appalachian land mass.
Directions and trail map.