The fauna of the United States of America is all the animals living in the Continental United States and its surrounding seas and islands, the Hawaiian Archipelago, Alaska in the Arctic, and several island-territories in the Pacific and in the Caribbean. The U.S. has arguably the most diverse fauna in the world and has many distinctive indigenous species found nowhere else on Earth. With most of the North American continent, the U.S. lies in the Nearctic faunistic realm, a region containing an assemblage of species similar to Northern parts of Africa and Eurasia. An estimated 432 species of mammals characterize the fauna of the continental U.S. More than 800 species of bird and there are more than 100 000 known species of insects. There are 311 known reptiles, 295 amphibians and 1154 known fish species in the U.S. Known animals that exist in all of the Lower 48 include white-tailed deer, bobcat, raccoon, muskrat, striped skunk, barn owl, American mink, American beaver, North American river otter and red fox. The Red-tailed Hawk is one of the most widely distributed hawks not only in the U.S., but in the Americas.
Huge parts of the most beautiful parts of the country with the most distinctive indengious wildlife are protected as national parks. In 2013, the U.S. has more than 6770 national parks or protected areas, all together more than 1,006,619 sq. miles (2,607,131 km2). The first national park was Yellowstone National Park in the State of Wyoming, established in 1872. Yellowstone National Park is widely considered to be the finest megafauna wildlife habitat in the U.S. There are 67 species of mammals in the park, including the gray wolf, the threatenedlynx, and grizzly bears.