Channel Islands National Park is home to a wide variety of significant natural and cultural resources. It was designated a U.S. National Monument on April 26, 1938, and a National Biosphere Reserve in 1976. It was promoted to a National Park on March 5, 1980.
Over 2,000 species of plants and animals can be found within the park. However only three mammals are endemic to the islands, one of which is the deer mouse (Peromyscus maniculatus) which is known to carry the sin nombre hantavirus. Spotted Skunk and Channel Islands Fox also are endemic. Other animals in the park include Island Scrub Jays, harbor seals, sea lions, island fox, spotted skunk, island night lizard, barn owls, American kestrels, horned larks and meadowlarks and California brown pelican. One hundred and forty-five of these species are unique to the islands and found nowhere else in the world. Marine life ranges from microscopic plankton to the endangered blue whale, the largest animal ever to live on earth. Archeological and cultural resources span a period of more than 10,000 years.
The park consists of 390 mi² (1010 km²), half of which are under the ocean, and include the islands of:
Although the islands are close to the shore of densely-populated southern California, their isolation has left them relatively undeveloped.