About an hour northeast of NYC near Croton Falls, the East Branch of the Croton River is known for its monster fish. The East Branch of the Croton River has two popular sections for fly fishing: East Branch Reservoir Outlet and Diverting Reservoir Outlet.
The East Branch Reservoir Outlet (aka Sodom) section runs from East Branch Reservoir to Diverting Reservoir (about 2.4 miles) near the town of Southeast. There is good year-round fly fishing access from SR22. While there are a few fild brown trout, this section is known for its trout stocked in April. This section has a artificial lures policy and there is a daily limit of 1 fish over 14 inches.
The Diverting Reservoir Outlet section runs from the outlet of Diverting Reservoir downstream to Muscoot Reservoir (about 2.5 miles) near the town of North Salem. There is fly fishing access from SR22. While there are a few fild brown trout, this section is known for its trout stocked in April. There is a daily limit of five fish of any size.
A good place to start is known as Bathtub Pool. It is located off SR22 in Brewster near the intersection with old SR22. You can see it from the bridge. Make sure to check out some of the deep holes, including Phoebe Hole.
Note: since this is a suburban river, it can get very crowded on the weekends. Try weekdays for a more solitary experience. While most people consider this to be a wet fly stream, feel free to try out some dry flies, too.
Note: A free Public Access Permit is required to fly fish on the East Branch of the Croton River.
Overall, East Branch Croton River is the 1st most popular fly fishing river of all 32 fly fishing spots in New York.