Maryland Route 138

Maryland Route 138
MD 138 highlighted in red
Route information
Maintained by MDSHA
Length	9.24 mi[1] (14.87 km)
Existed	1927–present
Tourist routes	Horses and Hounds Scenic Byway
Major junctions
West end	MD 45 in Hereford
Major intersections	MD 562 in Shepperd
East end	MD 23 near Shawsville
Location
Country	United States
State	Maryland
Counties	Baltimore, Harford
Highway system
Maryland highway system Interstate US State Scenic Byways
← MD 137 → MD 139

Maryland Route 138 (MD 138) is a state highway in the U.S. state of Maryland. The state highway runs 9.24 miles (14.87 km) from MD 45 in Hereford east to MD 23 near Shawsville. MD 138 connects northern Baltimore County with northwestern Harford County via the community of Monkton on Gunpowder Falls. The first section of the state highway was built east of Monkton in the 1910s. The remainder of MD 138 was built west of Monkton in the mid-1920s and east of Monkton in the early to mid-1930s. The state highway through Monkton was maintained by Baltimore County from the late 1960s to the mid-1990s, during which the highway was relocated at Gunpowder Falls.