Lake Ronkonkoma is a natural freshwater lake on Long Island, located around 8 miles (or 13 kilometers) northeast of the town of Islip, New York.
Most of Lake Ronkonkoma is less than 15 feet deep but it reaches depths of up to 65 feet in places. Formed by ancient glaciers and covering an area of 243 acres, Lake Ronkonkoma is the largest freshwater lake on Long Island, and has a shoreline length of 2.23 miles (or 3.59 kilometers).
Lake Ronkonkoma is open to the public for recreational boating and fishing, and there is an accessible fishing pier located in the Suffolk County Park off of Shore Road at the north end of the lake. Most of the shoreline of Lake Ronkonkoma is within Lake Ronkonkoma County Park and fishing those areas of Suffolk County Park property requires a Suffolk County Green Key.