The Oswegatchie River flows approximately 137 miles from its headwaters at Partlow Lake in Hamilton County through northern New York's Adirondack Mountains before emptying into the St. Lawrence River. The river is characterized by varied terrain, meandering through wilderness areas, offering both wild, rapids-filled sections with significant drops in elevation as well as slower, wider sections with minimal elevation change. Flowing through St. Lawrence County, the river features nearly 40 public access points and provides excellent fishing opportunities for a variety of warmwater and coldwater species. The river can be split into two distinct sections: the upper portion from Newton Falls to Hailesboro featuring a wild section with a 970-foot drop containing rapids, dams and good trout habitat, and the lower 67-mile portion from Hailesboro to Ogdensburg which is wider and slow-moving with only a 200-foot vertical drop, creating excellent habitat for warmwater species.