New Hampshire Route 13

NH 13 begins as a continuation of Massachusetts Route 13 at the state line between Brookline and Townsend, Massachusetts. It continues north for about 8.4 miles (13.5 km) through Brookline and crosses into Milford, where it meets an interchange with New Hampshire Route 101. The highway continues north for about 1.4 miles (2.3 km) through the outskirts of Milford's urban center until it reaches Union Square, better known as the Milford Oval, where it intersects New Hampshire Route 101A.

NH 13 continues north over the Souhegan River on the Colonel John Shepard Bridge, then turns northwest for 4.4 miles (7.1 km) towards Mont Vernon and serves as the town's main road. After intersecting the Francestown Turnpike in the center of Mont Vernon, NH 13 continues northwest for about 5.9 miles (9.5 km) until it intersects New Hampshire Route 136 in the center of New Boston. The highway then turns east, crossing the South Branch Piscataquog River, then goes northeast for 6.4 miles (10.3 km) along the path of the river toward Goffstown. It turns north at the intersection of New Hampshire Route 114 with which it briefly runs concurrently over the Piscataquog River and into downtown Goffstown.

After separating from NH 114 at the Goffstown Public Library, NH 13 continues north for 6.1 miles (9.8 km) to the town center of Dunbarton, then for another 3.5 miles (5.6 km) north where it intersects New Hampshire Route 77. After taking a sharp right at the intersection, NH 13 heads northeast towards Concord for 4.0 miles (6.4 km) until it reaches the interchange with Interstate 89 near a New Hampshire State Police barracks. NH 13 then turns north on South Street near downtown Concord, where it meets its northern terminus at US 202/NH 9.