A hundred years in the making, the National Wildlife Refuge system is a network of habitats that benefits wildlife, provides unparalleled outdoor experiences for all Americans, and protects a healthy environment. Today, there is at least one wildlife refuge within an hour’s drive of most major metropolitan areas. National wildlife refuges provide habitat for more than 700 species of birds, 220 species of mammals, 250 reptile and amphibian species and more than 1,000 species of fish. More than 380 threatened or endangered plants or animals are protected on wildlife refuges. Each year, millions of migrating birds use refuges as stepping stones while they fly thousands of miles between their summer and winter homes.