Stewart holds mountain biking races every year, so the course is very popular with local riders. Go there and expect to see many others enjoying the sport of mountain biking. The NY Department of Transportation demands that all riders acquire a free permit before riding. Fines will be issued to those without permit. 909 is an advanced placed to ride due to its numerous steep hills, loose terrain, and tight singletrack.
Trails there are varied.
The entire preserve is connected by a circle of fireroads. Branching off of the fireroads are a mix of singletrack trails, medium-width trails, and grassy trails. It is best to go to 909 with someone that knows its trails so you don't get lost. Also take serious consideration of not biking at 909 during hunting season because there are many inexperienced hunters that come out of NYC to hunt there. Norrie Point is a boat dock area on the Hudson River and Ogden Mills is a historic estate built by one of America's financial and industrial leaders during the Gilded Age, Morgan Lewis.