SENECA, river of the United States, in New York, is formed by the outlets of Canandaigua, Crooked, Seneca, Cayuga, Owasco, and Skeneatelas lakes. The western and remote source of the Seneca river is Mud creek, rising in the western part of On tario county, and flowing first north, thence north east, and finally east, receives the outlet of Canandai gua lake at Lyons, in Wayne county, after a compa rative course of 40 miles. At Lyons the stream takes the name of the Clyde, which flowing south-east by east 18 miles joins a much more considerable stream, the outlet of Crooked, Seneca, and Cayuga lakes, and assumes below the junction the name of Seneca river. Turning to a course nearly north one mile, the Seneca is crossed by the Erie canal, and one mile still lower passes the flourishing village of Montezuma, and continuing north four miles winds to the east eleven miles, receiving in the latter course the outlets of Owasco and Skeneatalas lakes. Now a considerable stream, the Seneca, turns NE. by E., and with a very winding lied joins the Oneida, and loses its name af ter a comparative course of about 100 miles from the source of Mud Creek.
The Seneca river gains importance from its valley being traversed 65 miles by the Erie canal, and from being the drain of the lake region of the western part of New York. The valley of the Seneca is, perhaps,
as a body of productive soil unsurpassed, and em bracing about 3600 square miles, sweeps over great part of the counties of Ontario, Wayne, Yates, Tom kins, Seneca, Cayuga, Courtland and Onondago coun ties. This region contains the saline tract of Onon dago, though otherwise not very productive in mine rals, though gypsum has been discovered. Geo graphically it extends from N. lat. 42° 15' to 43° 12', and is traversed between the Crooked and Seneca lakes by the meridian of Washington City. In re gard to climate the Seneca valley is remarkable as sloping from south to north. The surface of Crooked lake is a small fraction above 700 feet, whilst the junction of the Seneca and Oneida rivers rises only about 200 above the ocean level. The country drain ed by the sources of Crooked, Seneca, and Cayuga lakes is elevated upwards of one thousand feet above the tide level in Hudson, consequently the higher and lower extremes of the Seneca valley differ in tempe rature above two degrees of Fahrenheit from mere relative height, and gives a more rigorous climate to the southern than to the northern border. See next Article.