Maryland Route 806 is a state highway in the U.S. state of Maryland. The state highway runs a total of 4.05 miles (6.52 km) in two segments from U.S. Route 15 near Catoctin Furnace north to Roddy Creek Road near Thurmont. MD 806A, which has a length of 3.04 miles (4.89 km) from Catoctin Furnace to Thurmont, and MD 806R, which extends 0.55 miles (0.89 km) on the north side of Thurmont, are separated by a section of municipally-maintained road on the south side of Thurmont and a segment of MD 550 north of MD 77. MD 806 is the old alignment of US 15 through Catoctin Furnace and Thurmont. The state highway was originally constructed in the 1910s. MD 806 was assigned to the highway when US 15 bypassed Thurmont in the late 1950s. The state highway became a split route in the late 1980s. There have been several other segments of MD 806 along former sections of US 15 in Frederick County, including portions around Lewistown and south of Frederick.

Maryland Route 85 is a state highway in the U.S. state of Maryland. Known as Buckeystown Pike, the state highway runs 10.80 miles (17.38 km) from MD 28 in Tuscarora north to the Frederick city limit north of Interstate 70 (I-70), where the highway continues north as East Street. MD 85 connects Tuscarora and Buckeystown in southern Frederick County with the county seat of Frederick. The state highway also links the suburban area between Buckeystown and Frederick with I-70 and I-270. MD 85 is the old alignment of U.S. Route 15, which was originally constructed between Tuscarora and Frederick in the late 1910s and early 1920s. MD 85 was assigned to the highway in 1970 when US 15 was moved to a new highway heading north from its Potomac River crossing at Point of Rocks. The state highway was extended north to the city of Frederick as part of a project to overhaul MD 355's interchange with I-70 in the first decade of the 21st century.