• 532 BTEW YORK STATE MUSEUM 



Mines have been opened in Orange, Rockland, Westchester 

 and Putnam counties in this iron ore district and from the New- 

 Jersey line at the southwest to the Connecticut boundary on the 

 east. Their locations are shown on the map which accompanies 

 this report. Some of the largest and most productive mines in 

 Orange county have been worked more than a century.* This 

 county was famous for its iron manufacture during the Revolu- 

 tionary war.f The greatest development of the iron mines in 

 Putnam county has been since the opening of the Tilly Foster 

 and Mahopac mines or during the last twenty-five years. The 

 distance from public lines of transportation, the increased cost of 

 working the smaller " veins " at greater depths, the low prices 

 for iron ore and the competition with the richer ores of other 

 parts of our country have necessitated the suspension of work in 

 some of the mines and led to the permanent abandonment of 

 those most unfavorably situated. Of the 40 separate mines, 

 which have been ore producers. 10 only were in operation dur- 

 ing a part or the w r hole of the year 18S8. Their aggregate out- 

 put for that year amounted to 114,000 gross tons. The ores of 

 the Highlands district are the hard, crystalline magnetites. They 

 are generally rich, free from titanium, but contain a slight excess 

 of phosphorus above the limit for the manufacture of Bessemer 

 iron, excepting the Mahopac and Tilly Foster mines, which have 

 yielded a large amount of Bessemer ore, and a few small mines, 

 but which are no longer worked. 



II. The Adirondack Region, Including the Lake Champlain 

 Mines. — Magnetic Iron Ores. 



The Adirondack region, the great mountain plateau of north- 

 ern New York, is bounded by the valleys of Lake Champlain on 

 the east, of the St. Lawrence river on the north and northwest, 

 of Black river on the west, and the Mohawk on the south. It 

 occupies nearly all of "Warren, Hamilton and Essex counties, 

 the western and southern parts of Clinton, the southern parts of 

 Franklin and St. Lawrence, the eastern part of Jefferson and 

 Lew 7 is, the northern towns of Oueida. Herkimer, Hamilton and 



* Ore was discovered on the Sterl ng tract as early as 1750; the Forest of Dean mine was 

 pened about the same time. 



+ See "History of the Manufacture of Iron in all ages, 1 ' by James M. Swank, Philadelphia, 

 1884, pp. 102-106. 



