Channel Islands (California) in the context of "Southern California Bight"

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.

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.

Santa Rosae (also spelled Santarosae) was, before the end of the last ice age, an ancient landmass off the coast of present-day southern California, near Santa Barbara County and Ventura County, of which the northern Channel Islands of California are remnants. At its largest, Santa Rosae was roughly 3-4 times bigger than the northern Channel Islands of today, nearly 125 kilometers (78 mi) from east to west. Between about 20,000 and 5,000 years ago, Santa Rosae lost about 70% of its land mass to post-glacial rising sea level, leaving behind a vast submerged landscape currently being explored by scientists. San Miguel, Santa Rosa, Santa Cruz, and Anacapa Island comprise the unsubmerged portions of Santa Rosae today. This island was about 5 miles (8.0 km) offshore. It broke up between about 11,000 and 9,000 years ago, and the present northern Channel Islands took their shape after the continental ice sheets melted and sea levels rose by about 100 meters.

There is evidence to suggest that a now-submerged island, Calafia, lay between Santa Rosae and the mainland.

The Chumash are a Native American people of the central and southern coastal regions of California, in portions of what is now Kern, San Luis Obispo, Santa Barbara, Ventura, and Los Angeles counties, extending from Morro Bay in the north to Malibu in the south to Mount Pinos in the east. Their territory includes three of the Channel Islands: Santa Cruz, Santa Rosa, and San Miguel; the smaller island of Anacapa was likely inhabited seasonally due to the lack of a consistent water source.

Modern place names with Chumash origins include Malibu, Nipomo, Lompoc, Ojai, Pismo Beach, Point Mugu, Port Hueneme, Piru, Lake Castaic, Saticoy, Simi Valley, and Somis. Archaeological research shows that the Chumash people have deep roots in the Santa Barbara Channel area and have lived along the southern California coast for millennia.