El Camino Real (Spanish; literally The Royal Road, often translated as The King's Highway) is a 600-mile (965-kilometer) commemorative route connecting the 21 Spanish missions in California (formerly the region Alta California in the Spanish Empire), along with a number of sub-missions, four presidios, and three pueblos. Historically associated with the Calle Real which terminates in Mexico City, as the former capital of New Spain and the seat of royal power for Las Californias (hence “Real”), its southern end in the modern U.S. state of California is at Mission San Diego de Alcalá and its northern terminus is at Mission San Francisco Solano.
The name was revived in the American era in connection with the boosterism associated with the Mission Revival movement of the early 20th century. Streets throughout California bear the "El Camino Real" name. The route has been continually upgraded and is decorated with Commemorative bell markers.
Spanish and Mexican era
In earlier Spanish colonial times, any road under the direct jurisdiction of the Spanish crown and its viceroys was considered to be 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. The original route begins in Baja California Sur, Mexico, at the site of Misión de Nuestra Señora de Loreto Conchó, present day Loreto, (the first mission successfully established in Las Californias).
The Portolá expedition of 1769 included Franciscan missionaries, led by Junípero Serra. Starting from Loreto, Serra established the first of the 21 missions at San Diego. Serra stayed at San Diego and Juan Crespí continued the rest of the way with Gaspar de Portolá. Proceeding north, Portolá followed the coastline (today's California State Route 1), except where forced inland by coastal cliffs.
Eventually, the expedition was prevented from going farther north by the entrance to San Francisco Bay, the Golden Gate. Crespí identified several future mission sites which were not developed until later. On the return trip to San Diego, Gaspar de Portolá found a shorter detour around one stretch of coastal cliffs via Conejo Valley.
Portolá journeyed again from San Diego to Monterey in 1770, where Junipero Serra (who traveled by ship) founded the second mission (later moved a short distance south to Carmel). Carmel became Serra's Alta California mission headquarters.
The Juan Bautista de Anza expedition of (1775–76) entered Alta California from the southeast (crossing the Colorado River near today's Yuma, Arizona), and picked up Portolá's trail at Mission San Gabriel. De Anza's scouts found easier traveling in several inland valleys, rather than staying on the rugged coast. On his journey north, de Anza traveled the San Fernando Valley and Salinas Valley. After detouring to the coast to visit the Presidio of Monterey, de Anza went inland again, following the Santa Clara Valley to the southern end of San Francisco Bay and on up the east side of the San Francisco Peninsula.
Between 1683 and 1835, Jesuit and Franciscan missionaries established a series of religious outposts from today's Baja California and Baja California Sur into present-day California. Heavy freight and long distance passenger movement was practical only via ships by a coastal water route.
To facilitate overland travel, mission settlements were approximately 30 miles (48 kilometers) apart, so that they were separated by one long day's 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. Tradition has it that the padres sprinkled mustard seeds along the trail to mark the windings of the trail's northward progress with bright yellow flowers, creating a golden trail stretching from San Diego to Sonoma.
Valuable seeds were brought to California also marking the Camino Real de Tierra Adentro with trees for different uses. For example, ash trees were the marker for where a spring was to be found, as seen to this day at the church of in Fresnillo, Zacatecas.