California State Route 12 and the terminus of El Camino Real in Sonoma

The city of Sonoma historically has been the terminus of the American Auto Trail known as El Camino Real. The Auto Trail since 1906 has terminated at Mission San Francisco Solano at the intersection of 1st Street East and Spain Street. Since August 1934, the city has been served by California State Route 12. California State Route 12 since being designated has always used Sonoma Highway, Napa Street and Broadway to traverse the downtown area. The California Highway Commission adopted a 13.8-mile-long freeway bypass in 1962 which had Kenwood and Schellville as terminus points.

Ultimately the freeway adoption for California State Route 12 was rescinded by the California Transportation Commission 1977. This blog serves to explore the history of both El Camino Real and California State Route 12 in Sonoma.

California State Route 12 can be seen passing through Sonoma along Sonoma Highway, Napa Street and Broadway on the 1951 United States Geological Survey Map.

Part 1; the history of El Camino Real and California State Route 12 in Sonoma

The origins of modern Sonoma are linked to 1823 when Padre José Altimira established Mission San Francisco Solano. Mission San Francisco Solano was unique from the other Catholic Missions of El Camino Real in several ways. It was one of two Missions constructed north of San Francisco Bay and the only one constructed by Mexican authorities versus the Spanish.

The route of El Camino Real was intended to solidify a path of travel between the Catholic Missions of Las Californias. In 1804 Alta California was formed out of the larger Las Californias. El Camino Real would ultimately connect 21 Catholic Missions of Alta California ranging approximately 600 miles spanning from Mission San Diego de Alcala in San Diego north to Mission San Francisco Solano in Sonoma. Even after the advent of Mexican Alta California the path of travel through the established corridor of El Camino Real would remain the primary overland route.

In 1833 the Congress of the Union would pass the Mexican Secularization Act. This act ended Roman Catholic stewardship and removed control of large tracts of land associated with the Missions. Alta California governor José Figueroa would appoint Presidio of San Francisco Commandant Mariano Guadalupe Vallejo with responsibility of converting Mission San Francisco Solano into a town. The Sonoma town street grid would be plotted in 1835 and was laid out around a central plaza. The Sonoma civil government would be established in 1844.

Following the Mexican-American War much of Alta California would become the American State of California. Sonoma County was one of the original counties created on February 18, 1850. Sonoma was selected as the first Sonoma County seat, but it was a short-lived tenure. The county seat was moved to Santa Rosa in 1854 via a bill in the State Senate.

Sonoma can be seen at the then terminus of the Glen Ellen Branch Railroad and along multiple stage roads on the 1882 Bancroft's map of California. The Glen Ellen Branch was constructed from San Pablo Bay to Sonoma after the line incorporated in 1878. Sonoma would incorporate as a city on September 3, 1883.

Sonoma was ultimately designated as the northern terminus of the American El Camino Real which began being signed as an Auto Trail starting in 1906. El Camino Real entered Sonoma via Broadway towards the city plaza. The highway used Napa Street and 1st Street East to reach a terminus at Mission San Francisco Solano.

During the 1919 Third State Highway Bond Act Legislative Route Number 51 was added to the Highway System. Legislative Route Number 51 as originally defined was aligned between Santa Rosa east through Sonoma to Schellville. Legislative Route Number 51 would ultimately use Sonoma Highway, Napa Street and Broadway. Legislative Route Number 51 can be seen branching east of Santa Rosa towards Sonoma and Schellville on the 1920 Division of Highways State Map.

The 1934 California HIghways & Public Works would announce a portion of California State Route 12 as being overlaid onto Legislative Route Number 51. The alignment of California State Route 12 also used Sonoma Highway, Napa Street and Broadway.

California State Route 12 can be seen passing through Sonoma along Sonoma Highway, Napa Street and Broadway on the 1951 United States Geological Survey Map. Fundamentally the highway alignment has never been altered.

The March/April 1960 California Highways & Public Works announced the California Highway Commission was conducting studies on a 13.8-mile segment of freeway routing between Kenwood and Schellville. This corridor was intended bypass Sonoma and act as an extension of the Sebastopol-Kenwood freeway corridor adopted in 1957.

Selection of an adopted alignment for the Kenwood-Schellville segment of freeway was contentious. The Division of Highways preferred a modified Alternative P which appeared in the September 28, 1961, Press Democrat (courtesy cahighways.org). The Alternative P alignment bypassed Boyes Hot Springs, Sonoma and Schellville with a planned westerly routing. The freeway corridor strayed closely to much of the developed areas of El Verano.

The May/June 1962 California Highways & Public Works announced the California Highway Commission made a formal freeway alignment adoption in the Kenwood-Schellville corridor.

The Press Democrat announced on February 3, 1977, that the California Transportation Commission was seeking public comment on vacating the Kenwood-Schellville freeway adoption (courtesy cahighways.org). The adoption appears to have been rescinded as it no longer appears a planned routing of California State Route 12 in state documents.

Part 2; scenes along California State Route 12 and El Camino Real in Sonoma

Eastbound California State Route 12 departing Boyes Hot Springs enters Sonoma via Sonoma Highway. The State Route corridor makes a left-hand turn at Napa Street.

Eastbound California State Route 12 heads into downtown Sonoma where it turns right at Broadway and picks up El Camino Real.

These views of a California State Route 12 shield and El Camino Real bell can be found on westbound Napa Street approaching Broadway.

The plaza in Sonoma is bounded by Napa Street, 1st Street East, Spain Street and 1st Street West. This is one of the few Mexican-style plazas still present in a downtown area in California. Sonoma City Hall lies inside the plaza and was completed in 1908.

Mission San Franciso Solano and the terminus of El Camino Real can be found at the northeast corner of 1st Street East and Spain Street. The Mission structure is no longer an active church and has been part of Sonoma State Historic Park since 1909.