White Mountains, part of the Appalachian system, N N.H. and SW Maine, rising to 6,288 ft (1,917 m) at Mt. Washington in the Presidential Range and to 5,249 ft (1,600 m) at Mt. Lafayette in the Franconia Mountains. Crawford Notch separates these two main groups. Formed in the latter part of the Paleozoic era, the White Mts. are remnants of a much higher mountain mass. They are composed chiefly of granite and have been extensively glaciated. Much of the mountain area, c.1,200 sq mi (3,110 sq km), is included in White Mountain National Forest. Nationally noted for their varied and beautiful scenery, the White Mts. have long been one of the most popular year-round resort areas in the country.