SO NEW YORK STATE MUSEUM 
of elevation greater then than now at not less than 2000 feet because } 
the very end of the Hudson channel is submerged to that extent.’ | 
The coast was then at what is now the edge of the continental | 
shelf or platform about 100 miles east of the present coast line. |, 
That this greater altitude was before the Ice age is proved by the | 
fact that the inner Hudson channel now contains much glacial 
debris filling. That all of New York State was then higher than 
now is quite certain because, for example, with the lower Hudson 
region considerably elevated, the upstate region must also have | 
been elevated (though possibly not so much) in order to maintain 
the gradients of the actively eroding streams. 
To summarize briefly the drainage and physiography of the State 
during the Tertiary, we may say that, with a certain few important 
exceptions, the major features as we see them today were practi- 
cally the same toward the close of the Tertiary, and that these 
relief features were developed by erosion which began with the 
uplift of the great peneplain at the opening of this period or the 
close of the one just preceding. A few of the more notable differ- 
ences between the drainage of the late Tertiary and the present 
are as follows: Very few, if any, lakes, waterfalls, or gorges 
existed; Lakes Erie and Ontario were absent and these basins 
contained important streams which appear to have drained west- 
ward mto the Mississippi, the St Lawrence river probably had its 
source im the Thousand Islands region; the Mohawk river had its 
source on the divide at Little Falls, while the so-called Rome river 
flowed westward from Little Falls; West Canada creek entered the 
Rome river; the Sacandaga river entered the Mohawk; the State, 
especially the southeastern portion, was notably higher (perhaps 
not less than 2000 feet) than it now is so that the Atlantic coast 
line was about 100 miles farther out where the Hudson emptied 
ito the ocean; and Long and Staten islands did not then exist as 
such. 
1It has been suggested by Chamberlain and Salisbury (Geology, vol. 1, 
page 529) that the very end of the Hudson, and other submerged channels, 
may have been deepened by tidal scouring and, if so, the figure (2000 feet) 
generally given may be too high. At any rate the Hudson channel at the 
Highlands is submerged nearly 800 feet which certainly implies an altitude 
cf more than 1000 feet greater than now when the river was actively eroding. 
