Part 1; the history of US Route 99 in Salida
Salida was founded in 1870 as a siding of the Central Pacific Railroad when it's new line through San Joaquin Valley reached the Stanislaus County Line. Salida was thusly named as the Spanish word for "exit" as it was located at the San Joaquin/Stanislaus County Line. The Central Pacific Railroad (later Southern Pacific Railroad) laid the groundwork for development of San Joaquin Valley south of Stockton. Previous to the Central Pacific Railroad travel via wagon or foot in central California tended to avoid San Joaquin Valley in favor of the Stockton-Los Angeles Road. The Stockton Los Angeles Road lied to the east of San Joaquin Valley in the Sierra Nevada Foothills and was less subject flooding. Before the Central Pacific Railroad most of San Joaquin Valley was a sparsely inhabited wetland which made travel by road difficult. Salida can be seen along the Central Pacific Railroad on the 1873 Oregon, California, & Nevada Railroad Map.
The emergence of the automobile in the early 20th Century in California led to the 1909 First State Highway Bond Act which was approved by voters during 1910. The majority of the highways approved as part of the First State Highway Bond Act were largely well established routes of travel. One such highway was Legislative Route Number 4 ("LRN 4") which was defined as a highway from "Sacramento to Los Angeles."
US 99/LRN 4 through Salida by way of Salida Boulevard can be seen on the 1935 Division of Highways Map of Stanislaus County.
The May 1939 California Highways & Public Works features the reconstruction of US 99/LRN 4 between Salida and Modesto. Four miles of US 99/LRN 4 between the northern City Limits of Modesto northward into Salida were expanded to a four lane divided highway. The expansion of US 99/LRN 4 featured a new 23 foot wide Portland Cement travel surface being laid out opposite the existing highway. Traffic between Salida and Modesto is cited to have climbed over 10,000 vehicles per 16 hour daily survey by 1938.
US 99/LRN 4 in Salida as featured in the November/December 1947 California Highways & Public Works.
The recent four-lane expansion of US 99/LRN 4 north of Salida to the San Joaquin County Line is featured in the January/February 1948 California Highways & Public Works.
The September/October 1948 California Highways & Public Works cites the expansion of US 99/LRN 4 from Salida north to Ripon as being completed by August 1947. The new bridge over the Stanislaus River is cited as being completed by May of 1948.
The California Highways & Public Works publication ends in 1967 before CA 99 in Salida was upgraded to a freeway. The bridge structure on CA 99 at Hammett Road north of Salida show a date stamp of 1970. The completed CA 99 freeway through Salida appears on the 1970 Division of Highways Map.
Salida Boulevard is still a divided roadway which carries much of the structures which date to when it was expanded as part of US 99 in 1938. Salida Boulevard intersects Broadway Road which connects to CA 99 and CA 219. Salida Boulevard continues northward beyond Broadway Road where it eventually dead ends. US 99 would have intersected LRN 13/future CA 219 originally at the intersection of Salida Boulevard and Kiernan Avenue.