Dear Roberta:
 
In every part of the US there are associations of non-profit organizations
that have books full of corporate and foundation grant sponsors.  The best
place to start for this is the public library of a largist town or city.
These books are invaluable as they are updated annually and contain
information about the criteria of each granting organization, deadlines, areas
of interest, etc.
 
There is also a great deal of information on the Web - I don't have URL's
here, but there is a site, for instance, called "Grant Hotel" which is a good
place to begin.  I have also had success entering into a search engine
"Minnesota Grants".
 
The other place I would start is by asking the SHPO office in your area for
any leads on grants other organizations have received for heritage purposes.
The local grants tend to be smaller (you don't say what state you are in, so I
can't be more specific), while Rockerfeller Foundation, Ford Foundation etc.
are national in scope.  I believe the Getty Foundation might be interested in
a conservation project, for instance.
 
Anyway, hope this helps,
Karolyn Smardz