 MD 165 passes through western and northern Harford County, where it connects the communities of Fallston, Jarrettsville, Pylesville, and Whiteford.The state highway was constructed as part of MD 24 through Pylesville and Whiteford in the late 1910s and early 1920s.MD 165 from Baldwin through Jarrettsville to west of Pylesville was built in the late 1920s and early 1930s.