Sugarloaf Mountain is an example of a monadnock — an isolated hill or small mountain rising abruptly from gently sloping or level surrounding land.
It appears to be either an outlier to the east of the main mass of Catoctin Mountain, or a root remnant of the ancient Appalachian land mass.

The bedrock is the Lower Cambrian Sugarloaf Mountain Quartzite, a massive white quartzite interbedded with softer sericitic quartzite, slate, and phyllite.
 The formation is divided into upper, middle, and lower members.
Sugarloaf Mountain is an example of a monadnock — an isolated hill or small mountain rising abruptly from gently sloping or level surrounding land. It appears to be either an outlier to the east of the main mass of Catoctin Mountain, or a root remnant of the ancient Appalachian land mass.
The bedrock is the Lower Cambrian Sugarloaf Mountain Quartzite, a massive white quartzite interbedded with softer sericitic quartzite, slate, and phyllite.  The formation is divided into upper, middle, and lower members.
Sugarloaf Mountain (Maryland)