For anyone who has made White Oak Tree Road a part of your route between Syosset and Oyster Bay over the years, be advised that the off-road portion after the WOTR dead end is in really bad shape this year. Between overgrown brush and a huge tree that has fallen across the path, it's really no place for a road bike or a hybrid anymore.
Someone did cut a new dirt path to the right of the hill that leads onto the old path. It's rideable with a mountain bike (feels like the Greenbelt for a few minutes) but count on being a muddy mess when you get to the end.
If anyone knows of any other "secret" routes between Syosset and Oyster Bay (no Berry Hill or Split Rock Roads), please let me know.