Winchester to Keene NH 10 begins at the Massachusetts state line in Winchester, where it connects to Massachusetts Route 10. It runs northeast into the town center where it intersects with
NH 78 and
NH 119. NH 119 joins NH 10 briefly before splitting off to the east. NH 10 continues north along the
Ashuelot River, through the town of
Swanzey and into the city of
Keene. NH 10 meets
NH 12 and
NH 101 at a traffic circle near
Keene State College and turns west, joining the latter two routes to their intersection with
NH 9. At this intersection, NH 101 ends while NH 10 and NH 12 turn north onto NH 9 eastbound. The three overlapped routes pass west of downtown Keene for just over , then NH 9 and NH 10 exit NH 12 at a
trumpet interchange and turn northeast. NH 9 and NH 10 remain overlapped for another before NH 10 splits off to the north and crosses into the town of
Gilsum.
Gilsum to Lebanon NH 10 passes through Gilsum with no major junctions, then enters
Marlow, where it has a overlap with
NH 123. Continuing north, NH 10 meets the eastern terminus of
NH 123A then crosses into
Lempster. The highway has no major junctions in Lempster and continues north into
Goshen where it intersects the northern terminus of
NH 31. NH 10 continues into the town of
Newport, where it shares a brief concurrency with
NH 11 and
NH 103 in the town center. The highway continues through
Croydon with no major junctions, then into
Grantham where it intersects with the northern terminus of
NH 114 before interchanging with
Interstate 89. NH 10 joins I-89 at exit 13 and runs along the Interstate highway for , through the southwest corner of the town of
Enfield and into
Lebanon, where it leaves I-89 at exit 19.
Lebanon to Haverhill NH 10 exits I-89 onto
U.S. Route 4, which it immediately joins westbound. US 4 and NH 10 cross the
Mascoma River into the village of
West Lebanon, where they intersect with
NH 12A (providing local access to I-89). Just over to the north, US 4 splits off to cross the
Connecticut River into
White River Junction, Vermont. Now running along the eastern bank of the river, NH 10 continues north into the town of
Hanover. At
Dartmouth College in the heart of town, NH 10 meets its only child route,
NH 10A, a connector to
I-91 and
US 5 in
Norwich, Vermont, then intersects the northern terminus of
NH 120 (NH 120 is cosigned with NH 10 on North Park Street). NH 10 continues north into the town of
Lyme, where the only intersection of note is to East Thetford Road, a connector to
Thetford, Vermont, which becomes
Vermont Route 113 upon crossing the border to the west. Crossing into
Orford, NH 10 intersects and briefly overlaps
NH 25A before that route splits off to cross into
Fairlee, Vermont, and meet US 5. NH 10 continues into
Piermont and intersects with
NH 25 (connecting to
VT 25 just to the west) and
NH 25C. NH 25 turns onto NH 10 northbound, and the two routes are cosigned for into the neighboring town of
Haverhill. After crossing the town line, NH 25 splits off to begin its eastward trek across the state. NH 10 continues north along the Connecticut River and intersects the western terminus of
NH 116 in the village of
North Haverhill. Several miles to the north, NH 10 intersects the southern terminus of
NH 135 and enters the village of
Woodsville, where it reaches
US 302, which crosses into
Wells River, Vermont, just to the west. NH 10 officially ends at US 302, but is cosigned with it through
Bath,
Landaff,
Lisbon and into
Littleton to its intersection with
NH 18, just north of
I-93. ==History==