The Channel Islands, an island chain lying just off California's southern coast, appear quite close on clear days. Five of the eight islands and their surrounding one nautical mile of ocean, with its kelp forests, comprise Channel Islands National Park. In 1980, Congress designated Anacapa, Santa Cruz, Santa Rosa, San Miguel, and Santa Barbara Islands and 50,500 hectares (125,000 acres) of submerged lands as a national park because they possess outstanding and unique natural and cultural resources. The park provides habitat for marine life ranging from microscopic plankton to Earth's largest creature, the blue whale.

Seafaring Indians plied the Santa Barbara Channel in swift, seaworthy canoes called tomols. The Chumash, or "island people," had villages on the northern islands and traded with the mainland Indians. The southern island of Santa Barbara was home to the Gabrielino people. In 1542, explorer Juan Rodriquez Cabrillo entered the Santa Barbara Channel. Cabrillo, believed to be a Portuguese navigator in service to Spain, was the first European to land on the islands. While on his northbound odyssey of discovery Cabrillo wintered on an island he called San Lucas (San Miguel or possibly Santa Rosa Island). He died as a result of a fall suffered on that island and is believed to have been buried on one of the Channel Islands, but his grave has never been found. Subsequent explorers included Sebastian Vizcaino, Gaspar de Portola, and English Captain George Vancouver, who in 1793 fixed the present names of the islands on nautical charts. Beginning in the late 1700's, and on into the 1800's, Russian, British, and American fur traders searched the islands' coves and shorelines for sea otter. Because its fur was highly valued, the otter was hunted almost to extinction. Hunters then concentrated on taking seals and sea lions for their fur and oil. Several of these species faced extinction as well. In the early 1800's the Chumash and Gabrielino people were removed to the mainland missions.

Hunters, settlers, and ranchers soon came to the islands. By the mid-1800's, except for the fishermen who operated from cove camps, ranching was the economic mainstay. The Santa Cruz Island ranch produced sheep, cattle, honey, olives, and some of the finest early California wines. In the late 1800's the ranch on Santa Rosa Island was a major supplier of sheep to Santa Barbara and Los Angeles County markets. Anacapa, San Miguel, and Santa Barbara Islands also were heavily grazed or cultivated. In the early 1900's the U.S. Lighthouse Service — later the U.S. Coast Guard — began its stay on Anacapa Island. The U.S. Navy assumed control of San Miguel Island just before World War II. The islands served an important role in southern California's coastal defenses. The military's presence on San Miguel, Santa Rosa, and the other Channel Islands is evident even today.

A series of Federal and landowner actions have helped preserve these nationally significant island treasures. Federal efforts began in 1938, when President Franklin D. Roosevelt proclaimed Santa Barbara and Anacapa islands as Channel Islands National Monument. In 1976 a U.S. Navy and National Park Service agreement allowed supervised visitation of San Miguel Island. In 1978 a conservation partnership between the Nature Conservancy, a national nonprofit conservation organization, and the Santa Cruz Island Company provided for continued protection, research, and educational use of most of privately owned Santa Cruz. Finally, in 1980, Congress designated the four northern islands and Santa Barbara Island and the waters for one nautical mile around each as our 40th national park. Later that year the ocean six miles out around each island was designated as a National Marine Sanctuary. Today, Channel Islands National Park is part of the international Man and the Biosphere program to conserve genetic diversity and an environmental baseline for research and monitoring throughout the world.