Channel Islands National Park in the context of "Anacapa State Marine Reserve"

Anacapa Island (Chumash: Anyapax, meaning "mirage, illusion") is a small volcanic island located about 11 miles (9.6 nmi; 18 km) off Port Hueneme in Ventura County, California. The island is composed of a series of narrow islets 6 mi (10 km) long, oriented generally east–west and 5 mi (8 km) east of Santa Cruz Island. The three main islets, East, Middle, and West Anacapa, have precipitous cliffs, dropping off steeply into the sea.

Anacapa is the smallest of the northern islands of the Channel Islands archipelago, and is within the Channel Islands National Park. It is 9 miles (7.8 nmi; 14 km) across the Santa Barbara Channel from the nearest point on the mainland. It lies southwest of the city of Ventura, California. The northern waters of Anacapa Island are protected by the Anacapa State Marine Reserve, which is one of the MPAs existing in the Channel Island National Park.

The Channel Islands (Spanish: islas del Canal, Archipiélago del Norte) are an eight-island archipelago located within the Southern California Bight in the Pacific Ocean, off the coast of California. They define the Santa Barbara Channel between the islands and the California mainland. The four Northern Channel Islands are part of the Transverse Ranges geologic province, and the four Southern Channel Islands are part of the Peninsular Ranges province. Five of the islands are within the Channel Islands National Park. The waters surrounding these islands make up Channel Islands National Marine Sanctuary. The Nature Conservancy was instrumental in establishing the Channel Islands National Marine Sanctuary.

There is evidence that humans have lived on the Northern Channel Islands for thousands of years. Analysis of radiocarbon dating data indicates a continuous human presence starting between 8,000 and 11,000 years ago. The islands were inhabited primarily by two different Native American groups, the Chumash and the Tongva (Gabrieleño). The Channel Islands and the surrounding waters house a diverse ecosystem with many endemic species and subspecies. The islands harbor 150 unique species of plants.

Santa Cruz Island (Spanish: Isla Santa Cruz, Chumash: Limuw) is located off the southwestern coast of Ventura, California, United States. It is the largest island in California and largest of the eight islands in the Channel Islands archipelago and Channel Islands National Park. Forming part of the northern group of the Channel Islands, Santa Cruz is 22 miles (35 km) long and 2 to 6 miles (3 to 10 km) wide with an area of 61,764.6 acres (249.952 km).

The island's coastline has steep cliffs, large sea caves, coves, and sandy beaches. The highest point is Devils Peak, at 2,429 feet (740 m). A central valley splits the island along the Santa Cruz Island Fault, with volcanic rock on the north and older sedimentary rock on the south. This volcanic rock was heavily fractured during an uplift phase that formed the island, and over a hundred large sea caves have been carved into the resulting faults. The largest is Painted Cave, among the world's largest.