The Mount Washington Auto Road—originally the Mount Washington Carriage Road—is a 7.6 mi (12.2 km) toll road in southern Coos County, New Hampshire that extends from New Hampshire Route 16 in Green's Grant, just north of Pinkham Notch, westward across Pinkham's Grant and Thompson and Meserve's Purchase to the summit of Mount Washington in the White Mountains of the US state of New Hampshire. The road climbs 4,618 ft (1,408 m) from an altitude of 1,527 ft (465 m) at the bottom to 6,145 ft (1,873 m) at the top, an average gradient of 11.6%. The road was completed and opened to the public in 1861.

Green's Grant is a township in Coös County, New Hampshire, United States. As of the 2020 census, the grant had a population of zero. The grant lies within the White Mountain National Forest. The base of the Mount Washington Auto Road is located in Green's Grant.