Channel Islands National Park consists of five of the eight
Channel Islands off the Pacific coast of the U.S. state of California. Although the islands are close to the shore of the densely populated state, they have been relatively undeveloped. The park covers 249,561 acres (100,994 ha), of which 79,019 acres (31,978 ha) are federal land.[2]
Santa Cruz Island, the largest of the eight, is divided between The Nature Conservancy and the National Park Service. The Nature Conservancy owns and manages the western 76 percent of the island, while the eastern 24 percent is owned and managed by the National Park Service.[5]
The islands are home to significant natural and cultural resources, resulting in several designations.
The purpose of Channel Islands National Park is to protect and connect the public to the nationally significant natural, scenic, wildlife, marine, ecological, historical, archeological, cultural, and scientific values of the Channel Islands in the state of California.
History
Radiocarbon dating of a fire area near Arlington Canyon on the northwest coast of Santa Rosa Island shows human habitation from at least 37,000 years BP, while a burned mammoth bone was dated at 30,000 years BP. Similar fire areas in the same vicinity were dated at 27,000 years BP and 17,000 years BP, also believed to have been made by man. Additionally, a burned dwarf mammoth in a shell midden was dated to 12,500 years BP. A fire pit in a midden-humus layer was dated at 11,900 years BP, while above this layer was a stone chopper with a butchered and burned mammoth dated 11,800 years BP. Several more fire areas were dated at 11,000 years BP, while human bones, Arlington Springs Man, are dated to 10,000 years BP. A circular fishhook was dated at 4,800 years BP. Huge shell mounds appear at 2,000 years BP, while a camp fire in Skull Gulch was dated at 330 years BP.[10][11]
Juan Rodríguez Cabrillo first observed the islands in 1542. The three northern channel islands were inhabited by an estimated two to three thousand Chumash, with eleven villages on Santa Cruz, eight on Santa Rosa, and two on San Miguel.[12][13][14] In 1938 the Santa Barbara and Anacapa islands were designated a national monument. San Miguel, Santa Rosa and Santa Cruz islands were combined with the monument in 1980 to form modern-day Channel Islands National Park.[13]
Oil spill
Main article:
crude oil spilled into the Pacific Ocean, creating an oil slick with an area of about 800 square miles (2,100 km2).[13][16] Following the spill, tides carried the oil onto the beaches of the Anacapa, San Miguel, Santa Rosa and Santa Cruz islands.[16]
This spill had a large impact on native wildlife of the Channel Islands. Much of the islands' seabird population was affected, with over an estimated 3,600
avians killed. Meanwhile, seals, dolphins and other sea life died and washed ashore on both the islands and the mainland.[16][17]
formations. Aligned with the Santa Monica mountains, the Northern Channel Islands form a mountain system 130 miles long. This island chain appears to be a faulted east-west trending anticline. Major faults include the Santa Cruz Island Fault and the Santa Rosa Island Fault.[11]
: 1, 9
A
Ma. Just to the south of this schist is the Willows Diorite, also of the same age as the tonalite, or Late Jurassic. The only Cretaceous rocks consist of the Jalama Formation, found on San Miguel Island.[11]
: 11–14, 119
Late Eocene South Point Formation, while the Cozy Dell Formation is present on Santa Rosa, along with the Sespe Formation.[11]
: 17–19, 37, 45–46, 120–121
Middle Tertiary formations found on Santa Rosa and Santa Cruz include the
rhyolitic flows, flow breccias, and tuffaceous volcaniclastic beds. Middle Miocene Conejo Volcanics correlate with the bulk of Anacapa's lava flows, volcanic and volcaniclastic breccias, which consist of vesicular and porphyritic andesite erupting about 16 Ma. About 1700 m are exposed, with two strata of San Onofre Breccia interbedded at the base. Cores taken from the east end of the island are andesitic in composition. Santa Barbara Island consists of basalt-basaltic andesite and andesite volcanic flows, which erupted 15-17 Ma.[11]: 17, 48–55, 68–69, 80–83, 91, 121–122 [20][21][22][23][24]
During the
YBP. The 1994 Mammuthus exilis discovery on Santa Rosa near Carrington Point, was the first example of an in situ, almost complete, articulated skeleton.[10]: 319, 320, 323 [11]: 2, 83, [25]
Other geologic features of note on the islands include
horned lark and meadowlark and California brown pelican. One hundred and forty-five 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 on earth. Archeological and cultural resources span a period of more than 10,000 years.
Headquarters and mainland visitor center
The visitor center is located in the
Ventura Harbor. The visitor center contains several exhibits that provide information regarding all five islands, native vegetation, marine life and cultural history. Also, visitors can enjoy a short film, free of charge, that provides an overview of all five islands. The visitor center is open every day, except Thanksgiving and Christmas, from 8:30AM–5:00PM.[29] The average annual visitation to the mainland visitor center was around 311,000 in the period from 2009 to 2018, with 366,250 visiting in 2018.[4]
Recreation
Channel Islands National Park recreational activities include backpacking, camping, day hiking, scuba diving, and spearfishing. Channel Islands National Park is renowned for its large number of complex, beautiful sea caves. Kayaking through the sea caves is popular.
Based on ocean conditions and ferry availability, Scorpion Anchorage on Santa Cruz Island is the most visited area in the park for day and camping visitors. Camping visitors arrive at Prisoners Harbor[32] on the north shore and stay in the valley beyond. A new island visitor center opened at Scorpion Ranch on Santa Cruz Island on April 6, 2009.[33]
Although most visitation occurs in the summer, migrating gray whales and spectacular wildflower displays attract visitors in the winter and spring. Autumn is an excellent time to travel to the park, as well as for diving, as the days are usually sunny, with minimal winds and clear ocean water.
It is recommended that inexperienced visitors use caution when visiting the national park due to changing ocean conditions in this unique ecosystem. The National Park Service authorizes a small number of guide and outfitter services.[34]
Visitation includes about 30,000 visitors traveling to the islands and another 60,000 who sail within park waters.[citation needed]
^ abOrr, Phil (1967). Geochronology of Santa Rosa Island, California. Santa Barbara Botanic Gardens: Proceedings of the Symposium on the Biology of the California Islands. pp. 317–325.
^ abcdefghWeaver, Donald (1969). Geology of the Northern Islands. American Association of Petroleum Geologists Special Publication. p. 2.
^Crowe, Bruce; McLean, Hugh; Howell, David; Higgins, Ralph (1976). Howell, David (ed.). Petrography and Major-Element Chemistry of the Sanat Cruz Island Volcanics, in Aspects of the Geologic History of the California Continental Borderland, AAPG Miscellaneous Publication 24. Pacific Section, American Association of Petroleum Geologists. p. 196.
^Weigand, Peter; Savage, Karen; Reid, Tom; Chinn, Barbara (1998). Weigand, Peter (ed.). Composition of Volcanic Rocks on Santa Rosa, San Miguel, and Santa Barbara Islands, California, in Contributions to the Geology of the Northern Channel Islands, Southern California, MP-45. Bakersfield: Pacific Section, American Association of Petroleum Geologists. p. 37.
^Luyendyk, Bruce; Gans, Phil; Kamerling, Marc (1998). Weigand, Peter (ed.). 40Ar/39Ar Geochronology of Southern California Neogene Volcanism, in Contributions to the Geology of the Northern Channel Islands, Southern California, MP-45. Bakersfield: Pacific Section, American Association of Petroleum Geologists. p. 15.
^Agenbroad, Larry (1998). New Pygmy Mammoth (Mammuthus exilis) Localities and Radiocarbon Dates from San Miguel, Santa Rosa, and Santa Cruz Islands, California, in Contributions to the Geology of the Northern Channel Islands, Southern California, MP-45. Bakersfield: Pacific Section, American Association of Petroleum Geologists. pp. 169–175.