The state highway runs a total of 4.05 miles (6.52 km) in two segments from U.S. Route 15 (US 15) near Catoctin Furnace north to Roddy Creek Road near Thurmont.

MD 806 begins at an intersection with US 15 (Catoctin Mountain Highway) and Auburn Road, the old alignment of US 15 that heads south closely paralleling the southbound lanes of US 15.

MD 806 traverses High Run then reaches its northern terminus at the southern town limit of Thurmont.

[1][2] The roadway, which was formerly part of MD 806, continues north as municipally-maintained Frederick Road through a commercial area.

Frederick Road intersects Thurmont Boulevard, which heads west to a diamond interchange with US 15.

The old highway crosses Hunting Creek and turns north onto Water Street to pass through downtown Thurmont.

[1][3] The two sections of MD 806 through Catoctin Furnace and Thurmont and the intervening town streets are the old alignment of US 15.

On October 31, 2016, the portion of MD 806R between the northern border of Thurmont and Roddy Creek Road was transferred to county maintenance.