Between 1683 and 1834, Spanish missionaries established a series of religious outposts throughout the present-day California and the present-day 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 long day's ride on horseback along the 600-mile (966-kilometer) long El Camino Real , and also known as the California Mission Trail. 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, California began paving a section of the historic route in San Mateo County.  By the late 1920s, 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.

An unpaved portion of the original Spanish road has been preserved just east of Mission San Juan Bautista in San Juan Bautista, California.

In 1892, Anna Pitcher of Pasadena, California initiated an effort to preserve the as-yet uncommemorated route of Alta California’s Camino Real, an effort adopted by the California Federation of Women's Clubs in 1902.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 11-foot (3.4 m) high shepherd's crook, also described as "a Franciscan walking stick." The first of 450 bells were unveiled on August 15, 1906 at the Plaza Church in the Pueblo near Olvera Street in Los Angeles.

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 80, 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.

By Blanca Espa