By 1926, what is now NY 34 from Ithaca north to Cato was designated as part of NY 40, which continued northwest to Red Creek mostly by way of modern NY 370.
NY 34 was extended north from Cato to the super two highway carrying NY 104 around Hannibal in May 1970, taking over Cayuga County Route 40 and Oswego County Route 56 [REF].