Satellite view of Baja California peninsula

The Baja California peninsula (Spanish: Península de Baja California, meaning Lower California peninsula) is a peninsula in western Mexico. It extends some 1250 km (775 miles) from Mexicali, Baja California, in the north to Cabo San Lucas, Baja California Sur, in the south, separating the Pacific Ocean from the Gulf of California (or "Sea of Cortés"). The total area of the Peninsula is 143,396 km². The peninsula is connected to the mainland of Mexico by a strip of land that belongs to Sonora. There are four main desert areas on the peninsula: the San Felipe Desert, the Central Coast Desert, the Vizcaíno Desert and the Magdalena Plain Desert.

[edit] Geology

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The Baja California peninsula was once a part of the North American Plate, the tectonic plate of which mainland Mexico remains a part. About 5 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. Thereafter, the East Pacific Rise continued to propagate northward, up through what is now the Gulf of California. The propagating tip of the spreading center is now located somewhere in the Salton Sea basin. The Baja California peninsula is now part of the Pacific Plate and is moving with it away from the East Pacific Rise in a north northwestward direction. It is an ongoing example of a type of crustal block known as a terrane.

Just up the coast from Santa Rosalia, Baja California Sur is a prominent area of volcanic activity. The arid climate of Baja California allows the dramatic volcanic features of the landscape to stand out clearly for the visitor.

There are some points of dispute when it comes to stating specific detalis of Baja California's geologic history. However, there is a general agreement that the collision of the North American plate with the Pacific plate resulted in the creation of the mountains on Baja peninsula. The Pacific plate being thinner submerged under the North American thicker continental plate and formed a subduction zone resulting in the occurence of volcanoes. Currently, there are no active volcanoes on the Baja Peninsula. Upon the collision of the tectonic plates massive folds creased due to which the Pacific plate consisting of Baja and all land west of the San Andreas fault began to shift northwards and eventually tore the Baja peninsula off of the Mexican mainland. Naturally, this did not happen over night but over many millenniums. The Sea of Cortez was created when 5 million years ago when the process of opening was over and the sea filled it. The Sea of Cortez is over 600 miles long and more than 14,000 feet deep. Being positioned along the San Andreas Fault, it is seismically very active. Its long and narrow shape makes it produce one of the largest tidal ranges in the world with extreme water temperatures. can also vary by large extremes. Depending on the season and the location, the temperature can vary from a high of 91°F to a low of 47°F.

At the point of creation, there was much water since that was the period when the last ice age ended and the sea level rose drastically due to the ice melting. The low areas were filled in while the previously connected higher lands became islands in the sea. In the middle of the Sea of Cortez is the San Andreas fault. Its northward migration continues to this day. It is 669 miles long and extends from the mouth of the Colorado River in the north up to the southern end at Cabo San Lucas. Sediments from the Colorado River filled in a large delta at the northern end of the peninsula. It is today known as the Imperial Valley. This shortened the Baja peninsula which was originally much longer. Today it is 800 miles long and it is one of the longest peninsulas in the world. It is also very narrow – approximately 70 miles. The narrowest part is 26 miles wide. In the future, it can be expected that Baja California and the part of upper California west of the San Andreas fault will detach the continent and transform into a very long island.

[edit] History

In the minds of European explorers California existed as an idea before it was discovered. The earliest known mention of the idea of California was in the 1510 romance novel Las Sergas de Esplandián by Spanish author Garci Rodríguez de Montalvo. 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."

Following Hernán Cortés conquest of Mexico, the lure of an earthly paradise as well as the search for the fabled Strait of Anián, helped motivate him to send several expeditions to the west coast of New Spain in the 1530s and early 1540s. The first expedition reached the Gulf of California and California, and proved the Island of California was in fact a peninsula. Nevertheless, the idea of the island persisted for well over a century and was included in many maps. The Spaniards gave the name "California" to the peninsula and to the lands north, including both Baja California and Alta California, the region that became parts of the present-day U.S. states of California, Nevada, and others.

[edit] Partition

Photo of the marker

New Spain's province of California was divided into Alta California and Baja California on May 19, 1773 near San Juan Bautista Creek by Fray Francisco Palóu. A marker is erected in the place where the dividing committee began the measurements for the province's partition. The marker is behind the Misión San Miguel Arcángel de la Frontera, near Ensenada, Baja California.

Translated into English, the inscription on the marker reads:

San Juan Bautista Creek (Crespi, May 1 for the setting of the first international division line between Old or Lower California (Dominicans) and New or Upper California (Franciscans) five leagues to the north (Valley of the Medanos) being established by: Priest Francisco Palou on 19 August 1773 (Mojonera of Palou) in compliance with the instructions put forth on the April 7, 1772 Concordato. Rosarito Historical Society, Baja California A.C. at The Mission, Baja California, on 20 May 1990. Fieldwork and research: Mario Reyes Meléndez. Monument donation: Christenson - Carrozo Family. Construction: Students of the School of Tourism at U.A.B.C.(Autonomous University of Baja California).

[edit] Territory

The whole peninsula of Baja California was a Spanish, then Mexican territory from 1804 until 1931.

[edit] Timeline

• 1532: Hernán Cortés sends three ships north along the coast of Mexico in search of the Island of California. The three ships disappear without a trace.
• 1533: Cortés sends a follow-up mission to search for the lost ships. Pilot Fortún Ximénez leads a mutiny and founds a settlement in the Bay of La Paz before being killed.
• 1539: Francisco de Ulloa explores both coasts.
• 1690s–1700s: Spanish settlement in California
• 1804: The Spanish colony of California is divided into Alta ("Upper") and Baja ("Lower") California.
• 1847:The Battle of La Paz and the Siege of La Paz occurs, as well as several other engagements.
• 1850: after Alta California annexed by the United States, Baja California is divided into northern and southern territories.
• 1853: William Walker, with 45 men, captures the capital city of La Paz and declares himself President of the Republic of Lower California. Mexico forces him to retreat a few months later.
• 1930: Baja California is further divided into Northern and Southern territories.
• 1952: The North Territory of Baja California becomes the 29th state of Mexico, Baja California. The southern portion, below 28°N, remains a federally administered territory.
• 1973: The 1700 km (1060 miles) long Trans-Peninsular Highway (Mexican Federal Highway 1), is finished. It is the first paved road that spans the entire peninsula.^[1] The highway was built by the Mexican government to improve Baja's economy and increase tourism.^[2]
• 1974: The South Territory of Baja California becomes the 31st state, Baja California Sur.
• 1989: Baja California elects Ernesto Ruffo Appel the first non PRI governor since 1929.

[edit] Political divisions

The peninsula is divided into two parts:

• The northern part is the state of Baja California.^[3] The citizens of Baja California are named Baja-Californiano (Lower-Californian in English).
• The southern part, below 28° north, is the state of Baja California Sur. The citizens of Baja California Sur are named Sud-Californiano (South-Californian in English).
• Mexicali is the capital of the state of Baja California.
• La Paz is the capital of the state of Baja California Sur.

[edit] Geographic features

A series of mountain ranges runs the length of the peninsula, which are known as the Peninsular Ranges, and extend into Southern California.

• The Sierra Juárez is the northernmost range in Mexico.
• The Sierra San Pedro Mártir lies south of the Sierra Juárez, and is higher. The highest point is Cerro de la Encantada, 3096 m.
• The volcanic complex of Tres Virgenes lies in Baja California Sur, near the border with the state of Baja California.
• The Sierra de la Giganta runs along the shore of the Gulf of California south of the Tres Virgenes complex.
• At the south end of Baja California Sur, the Sierra de la Laguna forms an isolated mountain range rising to 2406 m.
• The Bahía de los Ángeles is a bay located on the east side of the peninsula facing the Gulf of California.

[edit] Ecoregions

The peninsula is home to several distinct ecoregions. Most of the peninsula is deserts and xeric shrublands, although pine-oak forests are found in the mountains at the northern and southern ends of the peninsula. The southern tip of the peninsula, which was formerly an island, has many species with affinities to tropical Mexico.

• California chaparral and woodlands, which covers the Mediterranean climate northwestern corner of the peninsula, as well as Cedros and Guadalupe islands.
• Sierra Juarez and San Pedro Martir pine-oak forests in the upper reaches of the Sierra Juárez and Sierra San Pedro Mártir ranges in the northern peninsula.
• The Sonoran Desert extends into the northeastern portion of the state, east of the Sierra Juárez and Sierra San Pedro Mártir.
• The Baja California Desert extends along the Pacific side of the peninsula for most of its length.
• The Gulf of California xeric scrub extends along the Gulf of California side of the peninsula for most of its length.
• San Lucan xeric scrub lies in the lowlands of the peninsula's southern tip.
• Sierra de la Laguna dry forests are found on the lower slopes of the Sierra de la Laguna.
• Sierra de la Laguna pine-oak forests are found at higher elevations in the Sierra de la Laguna.

[edit] See also

• Spanish missions in California
• Las Californias

[edit] Notes

[edit] References

This article includes a list of references, related reading or external links, but its sources remain unclear because it lacks inline citations. Please improve this article by introducing more precise citations where appropriate. (December 2009)

• Baja California State Government: History

Coordinates: 29°N 114°W / 29°N 114°W / 29; -114