The remarkable national parks systems in the United States is the result of effort of such early conservationists as John Muir, Theodore Roosevelt, Aldo Leopold, and Bob Marshall. The land conservation system has been started in 1872 by the creation of Yellowstone National Park. Today, the National Park Service administers 53 parks, 76 monuments, 10 seashores, and 12 preserves, totaling more than 109,000 square miles (280,000 km2).
The federal government also manages millions of acres of other public lands in the form of national forests, wildlife refuges, and gazing lands. Another 82,800 square miles (214,500 km2) of natural areas are protected by state entities.
Vast areas of Canada are protected by 34 national parks, 1.5 million square miles (3.9 million km2) of national forests, 46 national wildlife areas, and 101 national bird sanctuaries.
North America also offers an array of private preserves, such as the more than 1,100 reserves in USA operated by The Nature Conservancy and the 80 reserves and wildlife sanctuaries managed by the National Audubon Society. These sites rely on volunteers to help manage them, thus providing a way for nature lovers to practice ecotourism in the filed.