SULLIVAN, county of, New York, bounded by Delaware county of the same state, NW.; Ulster N. and NE.; Orange SE. and S.; and by Delaware river, separating it from Pike county of Penn sylvania, SW.; and from Wayne county of Pennsyl vania, \V. The longest line that can be drawn in this county is one very nearly clue N. and S., from the southern angle at the mouth of Mongarep creek, to the most northern angle, 39 miles; and the area being within a small fraction of 819 square miles; the mean breadth is about 21 miles. Ex tending in lat. from 41' 26' to N.; and in long. from t° 55' to 38' E. from that meridian of Washington city.
The surface of this county is elevated, broken by hills, and in part mountainous, and nearly the whole drained by creeks flowing into Delaware river. The northern part has a western declivity, and gives source to Beaver Kill, a confluent of the Popachton branch of Delaware river. The cen tral and southern part of the county declines south wardly, and is also drained into Delaware river by the Mongaret, Nevesink, and other creeks. By the levels taken on the Hudson and Delaware canal, the lowest part of Sullivan county must ex ceed 455 feet above the ocean level; and of conse quence, from its mountainous aspect and position, the arable soil must lie between 500 and at least 1000 feet of such relative height. It is probable that the mean height of the farms exceeds 800 feet, or an equivalent to two degrees of Fahrenheit in the mean temperature of the climate. This difference
is distinctly seen in the advance of spring and autumn in Sullivan, and in similar latitude on Hudson river.
The southeastern and lower part of Sullivan county has gained public importance and local advantage from affording a part of the route of Hudson and Delaware canal. This canal leaves the Delaware river at Carpenter's Point, at the mouth of Nevesink river, and in the western part of Orange county, and passes thence in a northeastern direction along the valleys of the Nevesink, Ron dont, and Waalkill, to the Hudson at Eddyville, nearly opposite Rhinebeck, and passes by the villages of Essopus, or Kingston, Marbletown, Mombacus, Warwassing, &c. The rise from tide water in Hudson 535 feet, and fall from the summit level to Delaware river 80 feet.
By the piast lists publishing at this time (May 1831), there are beside Monticello the seat of jus tice, post towns Bethel, Bloomingburgh, Cochecton, Fallsburgh, Forrestburgh, Grahamsville, Liberty, Nevesink, Philipsport, Rockland, Searsville, Thompsonville, Brookville, White Lake, Woodbourne, and Varsborough. In 1820 the popu lation amounted to 8900.