ADIRONDACKS, a group of mountains in north-eastern New York, U.S.A., in Clinton, Esser, Franklin and Hamilton counties, often included by geographers in the Appalachian system, but pertaining geologically to the Laurentian highlands of Canada. Unlike the Appalachians, the Adirondacks do not form a connected range, but consist of many summits, isolated or in groups, arranged with little appearance of system. There are about ioo peaks, ranging from 1,200 to more than 5,000ft. in height, and 42 more than 4,000ft. ; the highest peak, Mt. Marcy (called by the Indians Tahawus or "cloud-splitter"), is near the eastern part of the group and attains an elevation of 5,344ft. Other high peaks are McIntyre, 5,112ft.; Skylight, 4,920; Haystack, 4,918; and Whiteface, 4,872. These mountains, consisting of various sorts of gneiss, intrusive granite and gabbro, have been formed partly by faulting but mainly by erosion, the lines of which have been determined by the presence of faults or the presence of relatively soft rocks. The mountains form the wa ter-parting between the Hudson and the St. Lawrence rivers. On the south and south-west the waters flow either directly into the Hudson, which rises in the centre of the group, or else reach it through the Mohawk. On the north and east the waters reach the St. Lawrence by way of Lakes George and Champlain, and on the west they flow directly into that stream or reach it through Lake Ontario. The most important rivers within the area are the Hudson, Black, Oswegatchie, Grass, Raquette, Saranac and Ausable. Among the larger lakes are the Upper and Lower Saranac, Big and Little Tupper, Schroon, Placid, Long, Raquette and Blue Mountain. The surface of most of the lakes lies at an elevation of over i,5ooft. above the sea; their shores are usually rocky and irregular, and the wild scenery within their vicinity has made them very attractive to the tourist.
The region known as the Adirondack Wilderness, or the Great North Woods, embraces between 5,000 and 6,000 sq. m. of moun tain, lake, plateau and forest, which for scenic grandeur is almost unequalled in any other part of the United States. Rail ways and highways penetrate the heart of the region and small boats ply upon the larger lakes. Well-marked trails lead to the crests of the better-known peaks. The mountains are easily reached from Plattsburg, Port Kent, Herkimer, Malone and Saratoga Springs. Every year thousands spend the summer months in the wilderness, where cabins, hunting lodges, villas and hotels are numerous. The resorts most frequented are in the vicinity of the Saranac and St. Regis lakes and Lake Placid.
In the Adirondacks are some of the best hunting and fishing grounds in the eastern United States. At the head of Lake Placid stands Whiteface mountain, from whose summit one of the finest views of the Adirondacks may be obtained. Two miles south-east of this lake, at North Elba, is the old farm of the abolitionist John Brown, which contains his grave and is much frequented by visitors. Lake Placid is the principal source of the Ausable river, which for a part of its course flows through a rocky chasm from i oo to 175ft. deep and rarely over 3oft. wide. At the head of the Ausable chasm are the Rainbow falls. Another impressive feature of the Adirondacks is Indian pass, a gorge about um. long, between Mt. McIntyre and Wallface moun tain, a majestic cliff rising vertically from the pass to a height of 1,300 feet. Keene valley, in the centre of Essex county, is another picturesque region, presenting a pleasing combination of peaceful valley and rugged hills. Though the climate during the winter months is very severe—the temperature sometimes falling as low as —42°—it is beneficial to persons suffering from pul monary troubles and a number of sanatoria have been established. The region is heavily wooded with spruce, hemlock, pine and hardwood trees. Lumbering has been much restricted by the creation of a State forest preserve, containing in 1927, 1,884,643 ac., and by the purchase of large tracts for game preserves and recreation grounds by private clubs. The so-called Adirondack park, containing over 3,000,00o ac., includes most of the State preserve and large areas held in private ownership.
See S. R. Stoddard, The Adirondacks Illustrated (1894) T. M. Longstreth, The Adirondacks (1917), and the Reports of the New York State Geologist and the Bulletins of the New York State Museum.