Maryland Route 121

Maryland Route 121
Clarksburg Road
Maryland Route 121 highlighted in red
Route information
Maintained by MDSHA
Length	3.96 mi[1] (6.37 km)
Existed	1927–present
Major junctions
South end	MD 117 in Boyds
Major intersections	I-270 in Clarksburg
North end	Stringtown Road in Clarksburg
Location
Country	United States
State	Maryland
Counties	Montgomery
Highway system
Maryland highway system Interstate US State Scenic Byways
← MD 119 → MD 122

Maryland Route 121 (MD 121) is a state highway in the U.S. state of Maryland. Known as Clarksburg Road, the highway runs 3.96 miles (6.37 km) from MD 117 in Boyds north to Stringtown Road between Interstate 270 (I-270) and MD 355 in Clarksburg. MD 121 connects Boyds and Clarksburg in northern Montgomery County. The highway was paved from Clarksburg to Boyds in the early to mid-1910s. MD 121 was extended to north of Clarksburg in the late 1920s and early 1930s. MD 121 was relocated through Clarksburg in the mid-1950s when I-270 was constructed through the area. The highway's northern end was rolled back to MD 355 in the mid-1970s. MD 121 was relocated in Boyds in the mid-1980s. The highway's northern end was moved to its present terminus just north of I-270 when Stringtown Road was constructed in the mid-2000s. In addition to the Boyds–Clarksburg route, MD 121 has also included three disjoint segments in Dawsonville and Germantown. All three of these routes were segments of the original MD 119.