| Middle Branch Oswegatchie River | |
| Pushpin Map: | New York Adirondack Park#USA |
| Pushpin Map Caption: | Location of the mouth |
| Subdivision Type1: | Country |
| Subdivision Name1: | United States |
| Subdivision Type2: | State |
| Subdivision Name2: | New York |
| Subdivision Type3: | Regions |
| Subdivision Name3: | North Country, Central New York Region |
| Subdivision Type4: | Counties |
| Subdivision Name4: | Lewis, Herkimer, St. Lawrence |
| Source1: | Walker Lake |
| Source1 Location: | Northeast of Stillwater |
| Source1 Coordinates: | 43.9651°N -74.9463°W |
| Mouth: | West Branch Oswegatchie River |
| Mouth Location: | Harrisville |
| Mouth Coordinates: | 44.1228°N -75.3264°W |
| Mouth Elevation: | 821feet |
| Basin Size: | 108sqmi |
| Tributaries Left: | Lees Creek, Glasby Creek, Wolf Creek, Palmer Creek, Panther Creek, Browns Creek |
| Tributaries Right: | Sand Lake Outlet, Coyer Creek, Bassetts Creek, Pins Creek, Mullins Marsh Creek, Fish Creek |
Middle Branch Oswegatchie River is a river in northern New York. It begins northeast of the Hamlet of Stillwater and flows into the West Branch Oswegatchie River in Harrisville.[1] The Middle Branch mostly consists of shallow and fast-moving waters with only two or three slow-moving sections favorable for canoeists. These include Alder Bed Flow and another still-water section known locally as Moynehan Flow. The latter begins in the area where Lower South Pond Outlet runs into the river. Occasionally, experienced kayakers take advantage of high water conditions to ply its waters - generally from the Bear Pond Road, a few miles upstream of Alder Bed Flow, and downstream to another seasonal access road located near Mullins Flow. However, because they are seasonal roads and the area is so remote - this part of the river is seldom used. Brook trout exist as the primary sport-fish for the entire length of Middle Branch Oswegatchie. Chubs & bullheads are also present in its waters.