Really lovely succession forest preserve with a couple of short loops and one very long one, but with three access points and four-season hiking glory. The big draw here is obviously the three big waterfalls, although the cascade (Jacob's Ladder) at the lower end of the preserve is worth the hike, especially in high water (and we are told, when it freezes up).
We haven't been here in winter but the blue loop by the Mariaville Rd. Parking area looks like outstanding snowshoeing in season, as with the leaves down the view of the gorge is lovely and the slopes are gentle up and down. Once you cross the bridge over to the red trail, the slopes get trickier (lots of rocks and branches, and the occasional steep section, worse in wet conditions) but have nice side branches.
Be careful about doggy trails, as the markings on the main trails are erratic. There's no trash collection point so make sure you take in a garbage bag to help schlep out other peoples' garbage, your karma will thank you. Hiking shoes and water de rigeur, and this is the kind of trail I'd recommend throwing a loop of rope into your backpack on general principle, in case there's trouble, since there are some nasty drop-offs here and there and the slopes aren't entirely stable (as you can see from the various rather large slide areas).
The Coplon Rd. entrance point requires a bit more of a hike to get the full loop, but is likely to be less crowded, and has the advantage of coming in over cleared land so you get the full sense of the layers of succession.
Ignore the "official" website via the county and the small, not entirely up to date or helpful map available there, and try this great blog, which has a link to a much, much better topo map which also features a trail not marked on the official map:
http://hikingplotterkill.wordpress.com/
hikingplotterkill - dot - wordpress - dot - com
Downsides: it's well-traveled, since it's so accessible, so you won't get much solitude in good weather, and the incongruities of trail trash and the odd graffiti on trail structures is a bit jarring. read more