Originally Posted by
chasmm
Long Island has the reputation for being pretty flat (and it is...for the most part). However the North Shore does have some short climbs.
Bicycle routes 25 and 25A have some climbs, but I'm guessing nothing in the realm of what you're looking for. (The area by Cold Spring Harbor can get pretty hilly.)
I think your best bets are going to be Hunterdon county in NJ or the Bear Mountain area, both a little out of your driving range.
The area west of Summit, NJ is very hilly -- it's on the Watchung mountains -- but not that much closer. It has the advantage of easy access by train from Penn Station.