The book described the Island of California as being west of the Indies, "very close to the side of the Terrestrial Paradise; and it is peopled by black women, without any man among them, for they live in the manner of Amazons".

[1] The Baja peninsula was originally believed by the first Spanish sea explorers to be an island, and acquired the name California, after the mythical paradise.

Following Hernán Cortés's conquest of Mexico, the search for the fabled Strait of Anián connecting the Atlantic to the Pacific helped motivate him to send several expeditions to the west coast of New Spain in the 1530s and early 1540s.

[3] Although cartographers such as Abraham Ortelius showed the Baja as an extensive peninsula in his Theatrum Orbis Terrarum, published in Antwerpen in 1589, and on the map Maris Pacifici from 1589, in the first half of the 17th century the idea of California as an island spread again; this persisted well into the 18th century, and was included in many erroneous maps that did not have the knowledge of the Spanish sailors about the Pacific coast of North America.

[4] It is believed to have originated with Carmelite friar Antonio Ascension, who around 1620 drew a map of California depicting it as an island, supposedly on a misconception of reports by Spanish navigators Juan de Fuca and Martin d'Aquilar.

[5] A copy of this map was sent to Spain and was seized by the Dutch on its way and then reproduced in the Netherlands, and eventually found its way to Henry Briggs in London who widely disseminated this misinformation.

[6] Garcia and Jorge opined in 2023 that a reason for such a mistake could have originated in the secret in which the Spaniards held their cartography from other European powers' eyes.

[7] The final blow to the notion of California as an island was struck by an influential map created by Italian Jesuit priest Eusebio Kino during his mission in the Pimería Alta.

[8] Originally, in 1695, it depicted California as a peninsula but based on the presence of blue abalone shells (most likely Haliotis fulgens) from the Pacific coast in the Pimería Alta, the information from natives, and his own travels and sightings, Eusebio Kino redrew the map in 1701.

About 12 to 15 million years ago the East Pacific Rise began cutting into the margin of the North American Plate, initiating the separation of the peninsula from it.

Volcanoes of the peninsula and adjacent islands include:[15] Researchers from Scripps Institution of Oceanography have found a 2,000-year-old layer of non-decomposed roots, or peat, up to 4 metres (13 ft) under the desert mangroves.

This chain was formed primarily as a result of the subduction of the Farallon Plate millions of years ago all along the margin of North America.

Men adorned themselves with piercings in their ears and noses and wore accessories such as bracelets, belts, and necklaces made from bones or feathers.

Over time, women began wearing skirts and blouses made from willow husks, while men donned leather loincloths and went barefoot.

Women wore petticoats crafted from thin reeds woven with vegetable fibers and draped animal skins over their backs.

Following the missionary period, Cochimí descendants adopted elements of cowboy culture, influenced by sustained contact with cattle and sheep ranchers of European and North American descent.

Over time, the influences of modern civilization have significantly impacted Kumiai traditions, particularly among younger members of the community, who have gradually shown less interest in preserving their ancestral clothing practices.

This iconic outfit was designed by María de la Cruz Pulido following a state-wide contest organized by the government to represent Baja California's rich natural and cultural heritage.

Inspired by the region’s diversity, the attire consists of five pieces made of white cotton fabric, each imbued with symbolic meaning.

[23] The blouse includes an embroidered depiction of a woman with open arms, symbolizing the warmth and hospitality of the people of Baja California.