This is a fun weekday paddle, 45 miles from the Triborough Bridge, about 22 miles from the Tappan Zee Bridge. It is located in southern
Harriman State Park. Once you put in, you leave the road and you will not see any houses and it's all State Park, giving it a wilderness feel.
Based on the gradient lines on the map, the first mile is 40 fpm and the next 1 1/4 mile is 60 fpm (but seems steeper to me), where Pine Meadow Brook adds its water from the left. The first half is mostly CL2 with some CL3. Things start to pick up just before you see Pine Meadow Brook flowing in on the left. If you were shaky up to this point, I suggest that you carry out to the take-out or at least scout a lot; otherwise, you should be fine with boat scouting for the most part. Get out and scout if you can't see ahead.
Now it gets harder and is more of a CL3, CL3+ at low to medium. Lots of rock dodging, rock boofing and in a few spots I had to edge my kayak to sqeeze through boulders to go over a drop. I guess the drops range between 1-3 ft, mabe higher and often several in a row. You'll soon pass under a hikers' bridge and the left bank rises, I guess about 15-20 feet and you will pass between two large boulders. Go right; there's a log jam on the left and I am pretty sure the three creek-wide strainers are past this.
Always be on alert for strainers--it doesn't take much to block the path.
There's a hiking trail on the left of the creek not far from the put-in and it connects to another trail on the second part which leads to the parking lot which means you can hike on trails to scout the whole thing. If you start your hike at Reeves Meadow parking lot (it starts right side behind the center), you'll see red blazes but then veer left onto the yellow blaze that continues along the creek. Be sure not to follow Pine Meadow Creek further down, you need to veer left again to follow Stony Brook. This area is really popular with hikers and the parking lot gets full on a nice weekend day. On cold, wet days from late fall to early spring there will most likely be plenty of parking.
One more thing of note, this is really small and very rocky and real tight. If you are a canoeist, I don't know if this will work for you. Definitely, your canoe will get banged up - a lot.
Note: I was there 12/24/07. The ramapo at suffern gage (what you are viewing here) was at 2250cfs at 11:30 am. I was there physically around noon. The second half of this section was mostly a solid non-stop CL4, no breaks except where the brook goes under a construction bridge. At this level, you will not have to squeeze between rocks. You will be going fast and what few strainers that exist will be small and squirrely.
Ran this on Tuesday, March 30, 2010. I got there and the Ramapo gauge hit over 1500cfs and rising although heavy rains relented to drizzle. It was a definite CL4, very fun run. First half of the run did have a few short pools of moving water, the 2nd half did not have much of any. Eddies were practically non-existing. As far as Eddies, what you had was slower moving water in small spots along the banks, small swirly Eddies behind rocks, or eddie behind pour-overs, balancing to not get too close to the rock, or too far. Basically, it was almost one big rapid that varied in degrees of difficulty. It didnt rain that night and had to go back in the mourning. Although the Ramapo was still slightly rising, the Stony Brook level dropped, although with still a very decent flow for an easier run.
Interesting enough, although a recent snow/wind storm added a lot of wood in creeks more south in Westchester and as far up as Ulster, this Brook had less wood in it that I've ever seen. Since I was unable to upload this vid from my crappy phone, I uploaded it on youtube, it's the last and easiest rapid. Wish I had vid of some good stuff.
http://www.youtube.com/watch?v=Nj-wWq7jTAE
JD
Google Map of New York Whitewater