MD 119 is a four- to six-lane divided highway that connects several residential and commercial neighborhoods in Rockville, Gaithersburg, and Germantown.

Great Seneca Highway was planned by Montgomery County in the late 1960s as a local relief route for traffic on parallel Interstate 270 (I-270) between the three communities.

At the county highway, MD 119 enters the city of Gaithersburg and temporarily expands to six lanes until its intersection with Muddy Branch Road.

The highway crosses Muddy Branch and passes along the edge of the New Urbanist community of Kentlands before intersecting MD 124 (Quince Orchard Road).

On the western edge of the park, the state highway passes northeast of a Washington Suburban Sanitary Commission water treatment facility and enters the unincorporated suburb of Germantown.

The highway curves back north and intersects Wisteria Drive before reaching its northern terminus at Middlebrook Road east of Seneca Valley High School.

[1][3] Great Seneca Highway was proposed by Montgomery County in the late 1960s to relieve congestion along the I-270 corridor and provide a crucial link between Germantown and Rockville.

[5] However, in June 1987, the National Park Service reversed its ruling after Montgomery County agreed to build noise barriers and wildlife crossings and purchase land to compensate for the woods lost to construction of the highway.