Welcome, illig! Just down the road from us (we live in Watkins Glen, and I used to work in Corning)!
Check out
www.wnyoa.net for harescrambles and enduros, and
www.wnyma.com for motocross events. Unfortunately, trail riding is mostly on private land around here, and there's a couple places down in PA for public riding.
If you're thinking about joining a local club, Southern Tier Enduro Riders (my club) is based out of Elmira. We put on 2 harescrambles and an enduro every year, and we can always use an extra pair of hands. We also have club grounds for riding on (at least for 2003). Send me a PM or email if you're interested in joining.