North Dakota contains 63 National Wildlife Refuges, more than any other state. These 63 refuges encompass more than 290,000 acres. In addition, there are 11 Wetland Management Districts with over 254,000 acres of Waterfowl Production Areas. Depending of which refuge you are visiting, habitat may be comprised of native prairie (mixed and tall grass), wetlands, riparian and forested areas, all of which provide homes to resident wildlife, migratory birds and also endangered species such as the prairie-fringed orchid, piping plover, and whooping crane.Refuges in North Dakota are some of the best places to find prairie plants.

Patuxent Research Refuge, the nation's only National Wildlife Refuge established to support wildlife research, was created in 1936 by President Franklin D. Roosevelt. It has grown from 2,670 acres to 12,841 acres and encompasses land surrounding the Patuxent and Little Patuxent Rivers between Washington, D.C. and Baltimore, MD. Approximately 10,000 acres are forested, contributing to one of the largest blocks of contiguous forested habitat in the mid-Atlantic. Other habitat types include fields, marshes, scrub-shrub communities, and constructed impoundments. Both South Tract and North Tract areas are open to the public and offer hunting, fishing, wildlife observation, photography, trails, and interpretive programs.

Rachel Carson National Wildlife Refuge was established in 1966 in cooperation with the State of Maine to protect valuable salt marshes and estuaries for migratory birds. Located along 50 miles of coastline in York and Cumberland counties, the refuge consists of eleven divisions between Kittery and Cape Elizabeth. The proximity of the refuge to the coast and its location between the eastern deciduous forest and the boreal forest creates a composition of plants and animals not found elsewhere in Maine. Major habitat types present on the refuge include forested upland, barrier beach/dune, coastal meadows, tidal salt marsh, and the distinctive rocky coast.

Nestled at the beginning of California's Central Valley Bay-Delta, Stone Lakes National Wildlife Refuge is an urban refuge directly outside of the greater Sacramento metropolitan area. Established in 1994 to protect and enhance local and migratory wildlife and Central Valley habitats, the refuge's 6,421 acres of managed grasslands, wetlands, freshwater lakes and riparian forest provide critical resting, foraging and breeding habitat for hundreds of species in an area imperiled by fast encroaching urban development. Several plant species from the Refuge have been identified as being particularly useful for making phenological observations.

Trempealeau National Wildlife Refuge, established in 1936, lies within the Mississippi River flyway. This 6,226 acre refuge contains rolling prairies, rich wetlands and bottomland forests which support a variety of wildlife species. It is an isolated backwater, providing needed resting and feeding areas for waterfowl and other birds. The U.S. Fish and Wildlife Service is the principal federal agency responsible for conserving, protecting and enhancing fish, wildlife and plants and their habitats for the continuing benefit for American people. Several plant species from the refuge have been identified as being particularly useful for making phenological observations.

The William L. Finley National Wildlife Refuge was established in 1964 and consists of 5,706 acres encompassing a variety of habitats including seasonal wetlands, native prairie, oak savannah, riparian forests, and cropland. This land was set aside to preserve the specific wintering habitat requirements of the dusky Canada goose. By partnering with neighboring businesses and individuals, wildlife benefits from lands nearby the refuge as well. Habitat loss throughout the Willamette Valley has made the refuge increasingly more important for preserving native species biodiversity of both plants and animals.

Established in 1984 to preserve and protect a unique wetland habitat type - the pocosin - and its associated wildlife species, the refuge offers a diversity of habitat types including high and low pocosin, bogs, fresh and brackish water marshes, hardwood swamps, and Atlantic white cedar swamps. Visitors may also find black bears, deer, river otters, and red wolves, along with a variety of birds, reptiles, and amphibians. Whether paddling on the paddling trail, hiking or birding on the Sandy Ridge or Creef Cut Wildlife Trails, or taking a casual journey on the Wildlife Drive, visitors are sure to create memorable experiences.

The John Heinz National Wildlife Refuge at Tinicum is located in Philadelphia, Pennsylvania, about a mile from the Philadelphia International Airport. The refuge was created in 1972 to protect the last 200 acres of a once 5,700 acre freshwater tidal marsh, known as Tinicum Marsh, in Pennsylvania. The tidal marsh provides important habitat for over 300 species of birds, as well as fox, muskrats, fish, frogs, and a variety of plants. Several plant species from the refuge have been identified as being particularly useful for making phenological observations and are listed below.

Moosehorn National Wildlife Refuge, located in the Downeast region of Maine, was established in 1937 to protect and provide habitat for American woodcock and other migratory birds, endangered species, and other wildlife. The refuge is divided into two divisions, Baring (20,277 ac) and Edmunds (8,871 ac), and contains a myriad of habitat types, from rocky shores along Cobscook Bay to Northern hardwood and boreal forests. Moosehorn is recognized for being the only refuge in the system that has put most of its efforts into research and management for the American woodcock, a species of high conservation concern, by maintaining a mosaic of young even-aged forest stands, creating a multi-aged forested landscape.