The highway, which lies within Richford in northern Franklin County, has a length of 1.822 miles (2.932 km) from VT 105 north to the Canada–United States border.

VT 139 heads north along Main Street into the Downtown Richford Historic District.

VT 139 turns east onto Province Street, which curves northeast out of the downtown area.

The highway has a grade crossing with the Central Maine and Quebec Railway's Newport Subdivision rail line and parallels the rail line to the highway's northern terminus at the Richford–Abercorn Border Crossing at the international border between Vermont and Quebec.

The highway continues north from the border crossing as Quebec Route 139 (Chemin des Ormes).