In fact, any road under the direct jurisdiction of the Spanish crown and its viceroys was a "camino real". Examples of such roads ran between principal settlements throughout Spain and its colonies such as New Spain. Most caminos reales had names apart from the appended "camino real". Once Mexico won its independence from Spain, no road in Mexico, including California, was any longer a camino real. The name was rarely used after that and was only revived in the American period in connection with the boosterism associated with the Mission Revival movement of the early 20th century.
The route originated in Baja California Sur, Mexico, at the site of Misión San Bruno in San Bruno (the first mission established in Las Californias), though it was only maintained as far south as Loreto.
Between 1683 and 1834, Spanish missionaries established a series of religious outposts throughout the present-day U.S. State of California and the present-day Mexican states of Baja California and Baja California Sur. To facilitate overland travel, mission settlements were approximately 30 miles (48 kilometers) apart, so that they were separated by one day's long ride on horseback along the 600-mile (966-kilometer) long El Camino Real (Spanish for "The Royal Highway," though often referred to in the later embellished English translation, "The King's Highway"), and also known as the California Mission Trail. (The actual Spanish expression for "King's Highway" is "carretera del rey".) Heavy freight movement was practical only via water. Tradition has it that the padres sprinkled mustard seeds along the trail in order to mark it with bright yellow flowers.
In 1912, the State of California began paving a section of the historic route in San Mateo County. Construction of a two-lane concrete highway began in front of the historic Uncle Tom's Cabin, an inn in San Bruno that was built in 1849 and demolished exactly 100 years later. There was little traffic initially and children used the pavement for roller skating until traffic increased. By the late 1920s, the State of California began the first of numerous widening projects of what later became part of U.S. Route 101. Today the route through San Mateo and Santa Clara counties is designated as State Route 82.
Some older local roads that parallel these routes also have the name. Many streets throughout California today bear the name of this famous road, often with little factual relation to the original; but Mission Street in San Francisco and its counterpart in Santa Cruz do correspond to the historical route. A surviving, unpaved stretch of the road has been preserved next to the old Spanish mission in San Juan Bautista; this road actually follows part of the San Andreas Fault.
A common lingual faux pas is to call the road "The El Camino", which literally translates to "The The Road". Another common error is to interpret the Spanish (noun-adjective) order of words incorrectly and assume that "Camino" means "Royal" and "Real" means "Road", when in fact the reverse is the case.
Modern El Camino Real was one of the first state highways in California. Given the lack of standardized road signs at the time, it was decided to place distinctive bells along the route, hung on supports in the form of an high shepherd's crook, also described as "a Franciscan walking stick." The first of 450 bells was unveiled on August 15, 1906 at the Plaza Church in the Pueblo near Olvera Street in Los Angeles.
The original organization which installed the bells fragmented, and the Automobile Club of Southern California and associated groups cared for the bells from the mid-1920s through 1931. The State took over bell maintenance in 1933. Most of the bells eventually disappeared due to vandalism, theft or simple loss due to the relocation or rerouting of highways and roads. After a reduction in the number of bells to around 150, the State began replacing them, at first with concrete, and later with iron. A design first produced in 1960 by Justin Kramer of Los Angeles was the standard until the California Department of Transportation (Caltrans) began a restoration effort in 1996.
Keith Robinson, Principal Landscape Architect at Caltrans developed an El Camino Real restoration program which resulted in the installation of 555 El Camino Real Bell Markers in 2005. The Bell Marker consists of a 460 mm diameter cast metal bell set atop a 75 mm diameter Schedule 40 pipe column that is attached to a concrete foundation using anchor rods. The original 1906 bell molds were used to fabricate the replacement bells. The replacement and original bells were produced by the California Bell Company, are dated 1769 to 1906, and include a designer's copyright notice.