All 200 rolls of Holland Land Company records on microfilm are digitized, courtesy of FamilySearch.org. Scroll down to the tiny camera icons on the right. You will need to sign up for a free account.
Holland Land Company records at Cornell University
Account books for the Ellicottville Office in Cattaraugus County; correspondence and records including amounts paid on principal and interest, general expenditures, notes on improvements, and other material including land contracts and deed books for Allegany, Cattaraugus, Chautauqua, and Wyoming Counties. Includes records kept by purchasers of Holland Land Company holdings Nicholas Devereux and Co., Utica, N.Y. and the Farmers' Loan and Trust Co., New York City.
Microfilm of original volumes at the Erie County Courthouse in Buffalo, New York, scanned and browsable online. There is no name-searching capability so you have to click on a volume and read page by page, just like you would if you were doing this research in person in the County Clerk's office.
City of Buffalo Inactive Records & Research Facility
Has the following items, which are not digitized and must be viewed in person: - Tax & Assessment Roll Books - 1815-1837 (Bound Volumes) - Tax & Assessment Roll Books - 1838-1997 (Microfilm) - Assessors Land Maps - 1855, 1870, 1912 (Microfilm)