The northern portion of the route runs along the border, and actually crosses into and out of New Hampshire twice.

NH 113B starts at State Route 113 in Stow, runs approximately one mile west into New Hampshire, then turns north.

This intersection lies feet south of where State Route 113 crosses into North Chatham, New Hampshire.

This is the only instance in New Hampshire of a suffixed route carrying the numerics for a highway signed in another state.

New Hampshire Route 153 skirts the eastern shore of Province Lake and crosses the border into Parsonsfield, Maine, but maintains NH 153 signage throughout.