The upper loop of the byway begins in Emmitsburg, which is home to St. Joseph's College and Mother Seton Shrine. From here, the byway continues south along US 15 to Thurmont, which is a small town at the foot of Catoctin Mountain that is home to several covered bridges. The Old Main Streets Scenic Byway continues east on MD 77, passing through the community of Detour, which developed along the Western Maryland Railway. The byway continues east on Middleburg Road and reaches Uniontown, a small village with many country homes and the Uniontown Academy. Uniontown Road continues east to Westminster, which is home to McDaniel College and the Carroll County Farm Museum. From Westminster, the byway heads northwest on MD 140 and MD 832 to Taneytown, which was founded as an agricultural trading center. The upper loop of the Old Main Streets Scenic Byway continues along MD 140 back to Emmitsburg.