JEFFERSON COUNTY. 



This county is bounded on one side by Lake Ontario, and upon the other by the 

 wild, mountainous region which separates the waters of the Hudson River from 

 those of the St. Lawrence. It is intersected by the Black River, one of the most 

 picturesque streams of the State. Its surface is diversified : for about ten miles 

 back from the shores of the lake, it is nearly level ; we then reach the ledges of the 

 Trenton limestone, and the entire country becomes more elevated and irregular. 

 These natural features, implying an abundance of fish and game, joined to great 

 fertility of soil and easy cultivation, fitted this county for sustaining a large abori- 

 ginal population. We are not surprised, therefore, at finding here numerous traces 

 of former occupancy. These consist chiefly of enclosures of irregular outhnes, 

 situated, for the most part, upon the borders of the high table-land or terrace 

 formed by the abrupt termination of the great limestone deposit of the Trenton 

 group, the base of which, it is supposed, was formerly washed by the waters of 

 Lake Ontario. Quite a number of these works, however, occur upon the lower 

 terrace, in places where the natural features of the ground were favorable to their 

 construction and objects. Works were examined in this county, in the townships 

 of Watertown, Le Ray, Rutland, Rodman, Adams, and Ellisburgh. 



The following examples are presented in the order in which they were sur- 

 veyed. 



PLATE I. 



ANCIENT WORK, ADAMS TOWNSHIP, JEFFERSON COUNTY, NEW YORK. 



This work occupies a commanding position upon the brow of the second ter- 

 race, which is here some hundreds of feet in height, and very abrupt. The ground 

 immediately back of the site of the work is considerably depressed and swampy. 

 It is drained by a little stream (a), which, falhng over the cliff", forms a small but 

 picturesque cascade. The narrow channel of this stream was formerly obstructed 

 by a beaver-dam, which converted the marsh into a deep and impassable pond. 

 The elevation upon which this work is situated, it will thus be seen, was well fitted 

 by nature for defensive purposes, — possessing the two primary requisites, difficult 

 approach and an unfailing supply of water. 



The artificial defences consist of an embankment of earth, with an exterior 

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