Missisquoi National Wildlife Refuge is a National Wildlife Refuge located in the eastern shore of Lake Champlain in the U.S. state of Vermont. The refuge is in Franklin County in the northwest corner of the state near the International Boundary with Canada. It is the only National Wildlife Refuge located entirely in Vermont (Silvio O. Conte National Fish and Wildlife Refuge is partly in Vermont and three other states), and is administered by the United States Fish and Wildlife Service. The refuge was established on February 4, 1943, under the authority of the Migratory Bird Conservation Act. The initial acquisition was 1,582 acres (6.4 km2) of land in the Missisquoi River delta, including Shad Island and Big Marsh Slough. Additional land is acquired from willing sellers to fill in the refuge boundary. The refuge's current size is 7,232 acres (27 km2). It is located in the towns of Swanton and Highgate with satellite units in Derby, Vermont and Westville, New York. Habitat management Refuge lands support a variety of wildlife species and habitats including floodplain forest, wetlands, shrub, bog, grasslands, and upland areas. Lands are managed to provide and protect habitat for migratory birds, to preserve the natural diversity and abundance of plants and animals, to assist with recovery of threatened and endangered species. Federal wildlife laws and regulations are enforced to ensure the protection of habitat and wildlife. Maquam Bog is a 900-acre pitch pine woodland bog located on the northeastern margin of Lake Champlain, Vermont. It contains Vermont's largest populations of pitch pine, rhodora, and chain fern, a state-threatened species. The bog serves as an important wintering area for white-tailed deer and provides feeding and breeding areas for a variety of birds. Parcels of early successional hardwoods are rotationally clear cut in 8 - 10 year intervals in an effort to provide a variety of age class hardwood habitat for woodcock. Small clearcuts, usually 100 feet wide, are used on the refuge to create feeding, nesting and brood-rearing covers. Permanently mowed pieces of land adjacent to the clearcuts provide singing grounds and roosting areas for American woodcock. Woodcock, like ruffed grouse, turkey, white-tailed deer and a variety of songbirds all require forest habitat that is disturbed periodically to stimulate regeneration of dense hardwood stands that support declining woodcock populations throughout the east. Grasslands are periodically hayed, mowed or burned to keep open field from changing back to forest.