DRIFT DIVISION. 
161 
composed of boulders, rounded pebbles, gravel and sand.* They may be seen in the valley 
that extends south from Fishkill by Haight’s tavern, through the Highlands in Putnam county, 
to Coldspring and to Peekskill ;f and in most of the elevated valleys through which currents 
seem to have flowed, when the water was elevated some hundred feet above its present level.J 
On the island of New-York, these hills were very common in the present upper part of the 
city a few years ago, but most of them have been cut down in grading for streets.^ On Long 
island, these hills form an elevated ridge, called by some the “ Green mountains,” and by 
others the “ Backbone ” of the island, and extend from New-Utrecht by Brooklyn, Williams- 
burgh, Jamaica, Oysterbay and Smithtown, to Oysterpond point; and once extended perhaps 
to Plum island. Gull islands and Fisher’s islands.|| A branch of this ridge of drift hills extends 
from Smithtown through the south branch of Long island to Montauk point, and probably once 
extended to Block island.^! Both these ranges of hills are interrupted in many places, where 
channels seem to have been subsequently made across them. Staten island shows hills of 
the drift on its eastern part, at Forts Tompkins and Richmond. Many of the small islands 
in the narrows of Long island sound, and between there and New-York, show the same 
general characters. In many places, the islands that have drift deposits are covered more 
or less with some of the strata of the quaternary. The hilly region of Long island shows 
the characters of the drift deposits better perhaps than any other portion of our country, except 
the southeastern part of Massachusetts, where the hills are sometimes one hundred or two 
hundred feet high.** Some of these hills on Long island present elevations and depressions 
of one hundred feet or more, and the highest point of these hills is four hundred and four feet 
above the ocean. The country around Montauk point, on what is called Shawango neck (once 
an island), shows this hilly character of the drift to as great advantage as perhaps any other 
on Long island. The hills have a nearly uniform character, round-backed, with deep valleys 
without any approximation to regularity, unless their tendency to a bowl-shape be so 
construed. The valleys have no outlets, and the water that falls or drains into them, 
either sinks into the soil, or collects sc as to form “ pond-holes.” The hills are in form like 
potato hills, but disposed helter-skelter, and are from twenty to eighty or one hundred feet 
high. At the Shinnecock hills, west of Southampton, near Canoe place, and Dix hills, four 
* Mather’s Geological Survey of New-London and Windham counties in Connecticut (Norwich, 1834, p. 34.) Hitchcock’s 
Geological Report of Massachusetts. 1833, p. 144; 1835, p. 150; 1841, p. .360. 
f Mather on Diluvion ; printed for the Cadets of the United States Military Academy, 1835, p. 7. 
t The same kind of diluvial hillocks, as they are sometimes called, are in the valley of Wappinger’s creek, between Fishkill 
and Poughkeepsie; in the Mamakating valley, between Wawarsingand Wurtsboro’; between Johnstown and Hudson; the plains 
north of Valatie, Columbia county; in Greenbiish and Nassau ; on the road between Lansingburgh and Schaghticoke, in Rens¬ 
selaer county ; in the valley between Aineniaville and the Furnace four miles south; along the eastern part of Fishkill near the 
base of the mountains, near Shenadore and Stormville in Dutchess county, New-York. 
Gale. Geological Report of New York, 1839, p. 178. 
II Dr. Mitchill. Mineralogical and Agricultural Report, 1802. (Medical Repository, 1802, p. 214.) 
IT V'ide Alluvion, marine alluvial detritus, in this volume, p. 30; New-York Geological Report, 1838, p. 133; Mitchill in the 
Medical Repository, 1802, p. 213. 
** Hitchcock. Geological Report of Massachusetts, 1841, p. 367. 
Geol. 1st Dist. 21 
