Black Lake is the largest lake in St. Lawrence County with 63 miles of shoreline and a depth ranging between 8 and 40 feet (NYSDEC). Located in Morristown, the Water flows into the Lake from the Indian River, Grass and Black Creeks, and flows out of the Lake into the Oswegatchie River which connects to the St. Lawrence River.
The lake is regularly utilized for fishing and as a vacation destination, and large portions of its shoreline are developed with cottages and camps. Public access to Black Lake is provided in several locations. An improved concrete boat launch, maintained by the NYS Office of Parks, Recreation and Historic Preservation (OPRHP), is located on the northwestern shore of the lake off County Route 6. An unimproved car-top boat launch is located along State Route 58 near the hamlet of Pope Mills allowing access to Fish Creek approximately one mile upstream of the eastern shore of Black Lake. Shoreline fishing and informal launching of small watercraft are possible from a small island where Route 58 crosses a narrow northern section of Black Lake. Although Lonesome Bay State Forest approaches the southern portion of Black Lake, the shoreline itself is private property and public access to the water is not readily available from State Forest lands.