Merrymeeting Marsh is an extensive and diverse wetland system that is maintained by two large water-control structures. A dam in Alton maintains some 500 acres of wetland and one in New Durham floods an additional 222 acres. Both create excellent waterfowl nesting and feeding habitat. Two major streams, the Merrymeeting River and Coffin Brook, provide the water. The wetlands of Merrymeeting Marsh include: emergent and deep-water, scrub-shrub, forested wetlands and bogs. Uplands surrounding the marsh and the many islands within it are vegetated primarily with oak and white pine with a blueberry bush understory. There is a parking area and boat launch for cartop boats and canoes. Visitors are welcome to tour the hatchery during visiting hours.