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Former California State Route 41 over the 1910 Estrella River Bridge


The 1910 Estrella River Bridge is a truss span located in San Luis Obispo County which carried the original alignment of California State Route 41.  The structure was added to the State Highway System in 1916 as Legislative Route Number 33 and was assigned to the corridor of California State Route 41 in 1934.  The structure was bypassed in 1957 when the first unit of an expressway out of Paso Robles reached the Estrella River.  During 2020 the 1910 Estrella River Bridge was restored and modernized by San Luis Obispo County.  

Below California State Route 41 can be seen crossing the 1910 Estrella River Bridge on the 1943 United States Geological Survey map of Paso Robles.  




Part 1; the history of California State Route 41 over the 1910 Estrella River Bridge

The site of the Estrella River Bridge was surveyed by San Luis Obispo County Surveyor A.F. Parsons.  The structure was completed in 1910 by a construction company owned by C.W. Corbaley out of Los Angeles.  

The 1910 Estrella River Bridge would be added to the State Highway System as part of Legislative Route Number 33 (LRN 33).  LRN 33 was defined as part of the 1916 Second Highway Bond Act:

"an extension connecting the San Joaquin valley trunk line (LRN 4 and future US Route 99) at or near Bakersfield with the coast trunk line (LRN 2) and future US Route 101 in San Luis Obispo County, through Cholame Pass, by the most direct and practical route."

LRN 33 can be seen potted between Famoso and Paso Robles on the 1917 California State Automobile Association Map.


LRN 33 can be seen crossing the 1910 Estrella River Bridge via what was then called Shandon Road on the 1919 United States Geological Survey Map of Paso Robles.  The structure is noted to be named as "Fifteen Mile Bridge" on the map. 


During 1933 LRN 33 had been extended to a new terminus west of Paso Robles at LRN 56 in Cambria.  LRN 33 from Cholame west to Cambria was announced as part of California State Route 41 when the initial run of Sign State Routes was published in the August 1934 California Highways & Public Works.  California State Route 41 crossed the 1910 Estrella River Bridge west of Shandon.  From the river the highway followed Union Road and 13th Street to US Route 101 at Spring Street in downtown Paso Robles.  



Below California State Route 41 can be seen crossing the 1910 Estrella River Bridge on the 1943 United States Geological Survey map of Paso Robles.  


The May/June 1957 California Highways & Public Works announced a new expressway grade for California State Route 41 east of Paso Robles to the Estrella River was was in the process of being constructed.  


The July/August 1957 California Highways & Public Works announced the upcoming realignment of US Route 101/LRN 2 on the Paso Robles Bypass.  The Paso Robles Bypass Project is stated to be 5.1 miles in length which would tie into the existing divided highway segments on both ends of the city.  The Paso Robles Bypass Project included a tie-in with the recently completed realignment of California State Route 41 from Huerhuero Creek east to the Estrella River.  Upon being bypassed the road to the 1910 Estrella River Bridge came to be known as "River Grove Road." 




During June of 1958 the Division of Highways sought and obtained permission to relocate US Route 466 off of LRN 125 between Atascadero and Shandon.  The Division of Highways noted that California State Route 41/LRN 33 between Paso Robles-Shandon had recently been improved and was by far the favored highway for traffic.  LRN 125 between Atascadero-Shandon is noted to be substandard in design and despite being part of US Route 466 since 1933 was never signed as such.  US Route 101 through Paso Robles is noted to be in the process of going through a freeway upgrade.  The new alignment of US Route 466 would see it briefly multiplex California State Route 41/LRN 33 west of Shandon to Paso Robles via 24th Street and US Route 101/LRN 2 south to Atascadero via Spring Street. 

As part of the 1964 State Highway Renumbering US Route 466 was truncated to Baker.  California State Route 46 was assigned to a new corridor from Famoso west to Cambria.  California State Route 41 was rerouted away from Cambria to a new terminus in Morro Bay by way of Creston and Atascadero.  

In 2020 the 1910 Estrella River Bridge was restored by San Luis Obispo County.  The plaque attached to the structure lists Cori Marsalek as the project manager.  


Part 2; a drive to the 1910 Estrella River Bridge

The 1910 Estrella River Bridge is accessible from the modern California State Route 46 expressway by following westbound River Grove Road.  











A look at the 1910 and 2020 plaques on the structure.  


Views walking west along the 1910 Estrella River Bridge. 




An eastward view over the bridge.

Views from the 1910 Bridge north and south over the Estrella Riverbed. 


First through Third Bond Act era Portland Cement becomes apparent on the portion of River Grove Road west of Estrella Road.  River Grove Road ends just before reaching the California State Route 46 expressway.  











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