I had other plans for the summer, but this is becoming plan B. First long tour.
I think I'm doing the C&O to the Allegheny Trail to Pgh. then trying to get to ROUTE 5 (from the bike PA website) but I'm a little iffy on getting from Erie (Presque Isle) to Niagara. The DOT NY page is not very helpful. Common sense would suggest that there is a scenic park like deal that runs along lake Erie to the falls but I'm sure that's far too easy. Does anybody have any advice?
You would follow the lakeshore which is route 5. It is a signed bike route in NY. Adventure cycling's northern tier route follows the same road. I by-passed Buffalo so I can't help you downtown but I am told there is a bike path along the river there.
Recommend staying on the river trail, or use the cut across Grand Island.
If you have time for a detour, there is a bicycle museum in Orchard Park, southeast of Buffalo, on route 20 (or alt 20). Museum is small and a bit tacky but they have some amazing antique bicycles there and the people who run it are fun to talk to. http://www.pedalinghistory.com/