Some great WNY links I've collected:
http://www.154thny.com/154thnyReborn/FamilyHistory/SettlingWNY
Hstory of Leon, NY 1832
http://www.rootsweb.ancestry.com/~nycattar/towns/leon.htm
HISTORY OF CATTARAUGUS COUNTY, NEW YORK 1879
http://www.rootsweb.ancestry.com/~nycattar/1879history/leon.htm
Site of David Ross's farm Eldredge Rd, Leon NY
http://maps.google.com/maps?hl=en&q=eldridge%20rd%2C%20leon%20ny&psj=1&wrapid=tlif12914788543061&um=1&ie=UTF-8&sa=N&tab=wl
Map of the Holland Land Purchase
http://en.wikipedia.org/wiki/File:Map_of_the_Holland_Purchase.png
Holland Land Company Maps
http://www.wnylegacy.org/cdm4/results.php?&CISORESTMP=results.php&CISOVIEWTMP=item_viewer.php&CISOMODE=thumb&CISOGRID=thumbnail,A,1;altern,A,1;collec,A,0;notes,200,0;none,A,0;20;altern,none,none,none,none&CISOBIB=altern,A,1,N;collec,A,0,N;notes,200,0,N;none,A,0,N;none,A,0,N;20;altern,none,none,none,none&CISOTHUMB=20%20(4x5);title,none,none,none,none&CISOTITLE=20;altern,none,none,none,none&CISOHIERA=20;collec,altern,none,none,none&CISOSUPPRESS=0&CISOTYPE=browse&CISOROOT=%2FXFM001