The section of the state highway in Towson was built in the 1910s and the portion through Jacksonville to Jarrettsville was constructed in the late 1920s and early 1930s.

The gap in MD 146 through Loch Raven Reservoir was filled in two steps of maintenance swaps in the early 1960s and late 1970s.

MD 146 heads northeast as Dulaney Valley Road, a four-lane divided boulevard that passes along the west side of the Towson Town Center shopping mall and the campus of Goucher College.

The state highway meets Interstate 695 (Baltimore Beltway) at a partial cloverleaf interchange.

North of the Beltway, MD 146 is a five-lane road with a center left-turn lane that passes between the suburbs of Hampton to the east and Lutherville to the west.

MD 146 reduces to two lanes just north of Pot Spring Road and its traversal of Long Quarter Branch, which flows into Loch Raven Reservoir.

[1][2] North of Timonium Road, MD 146 fully enters Loch Raven Reservoir Park.

The state highway passes by the historic home Eagle's Nest as it leaves the reservoir valley.

[19] The bridge and the highway to the northern edge of the reservoir reservation were transferred to state maintenance in 1979, closing the gap between the two sections of MD 146.