What's the closest lake to Millerton with a nice park and/or beach?

In Gallatin, NY (about 14 miles away) you will find Lake TaghKanic State Park which is right next to Lake Taghkanic and has two nice beaches. boat launches, rowboat, paddleboat and kayak rentals, camp sites, playgrounds, playing fields, picnic areas, a rentable pavillion, a recreation hall and showers. You can hike, bike, swim, fish, hunt, cross country ski, snowmobile and sometimes even ice skate and ice fish there.