David:
        The various pre-1900 census capitulations, Federal as well as State,
usually have pretty good summaries by county or region of agricultural and
land use.  You might have to infer that the "unimproved" lands is what you
would call "forested land" but that is how it was recorded.   Even the
reports of the early state censuses (1825, 1835, 1845) will give some clue
as to degree of improved lands from which you could calculate unimproved
(forests?) based on a known county area.  The large volumes of the census
summaries are available at larger research libraries in special collections
or Gov. Doc.s  (State or Univerity libraries).  They have a lot of
summarized information that never shows up in the raw data schedules that
everyone uses for genealogy and such, especially the early state censuses.
        I'm working with early Holland Land Company records of 1800 -1806 in which
the amount of improved land is given for each Great Lot.  I thought it
would be a simple matter of measuring development of the agricultural lands
by calculating the ratio of improved vs unimproved lands.  The I realized
that not all of the land in each lot is "improvable" due ravines,
escarpments, water, swamps, etc. and would never show up in the "improved"
column.  I'll pick that project up again on some cold winter night.

        Dan W.

you wrote:
"I have a question concerning the total percent of forested land in New
York State befoe the 1900's."