Articles about the Southern Pacific Railroad’s so-called Mococo Line, originally the San Pablo & Tulare Extension Railroad Company, which connected Martinez and Tracy, California.
Built as a subsidiary of the Central Pacific Railroad, it gained its familiar “Mococo” nickname from one of the industries it served, the MOuntain COpper COmpany. It was largely unused except for freight car storage during the 1990s and 2000s.
The village of Bethany could, once upon a time, be found along the Southern Pacific Railroad’s Martinez-to-Tracy extension, just a few miles outside the latter city’s limits.
These days, few signs remain of Bethany: an old farm road that ends near the tracks is perhaps the most significant remnant. (A reservoir in the nearby Livermore Hills is named for the town, but is several miles distant.)
The Central Pacific Railroad built a depot at Bethany around 1878 along the extension, which was constructed as the San Pablo & Tulare Railroad; in the early Twentieth Century, this section of tracks appeared on USGS maps – including the one below from 1914 – as the Southern Pacific’s “San Francisco and New Orleans Line.”
Today, it is known to railheads as the “Mococo Line.” It was the construction of this extension that led directly to the birth of Tracy at the end of the 1870s.
Showing here (above) is a portion of the schedule for the San Joaquin Daylight for the segment during which it traversed the so-called “Mococo Line” (from MOuntain COpper COmpany) from Martinez to Tracy and back again, excerpted from the Southern Pacific’s official Timetable #10, issued on May 12, 1968.
A Southern Pacific promo shot of the steam-powered San Joaquin Daylight near Bakersfield in the 1940s
Following the SP’s practice of designating “east” and “west” on its timetables based on the location of its Market Street corporate headquarters in San Francisco, the “eastward” San Joaquin Daylight (Train 52, originating in Oakland) is actually heading south to Los Angeles, while the “westward” return trip (Train 51, originating in L.A.) is heading north to Oakland.
For decades, oil from Kern County was transported by rail in tank cars (appropriately dubbed “oil cans”) to this Associated Oil storage facility in Tracy, which served as a way station as the oil traveled to Port Costa.
In the aerial photo from 1926 (shown above and below), the tracks heading to the right are part of the Mococo Line, which is now a seldom-used single track that extends up through Byron and Brentwood into Antioch and Pittsburg.
In the distance, just right of center in the photograph is an oil reservoir (also known back then as the “Gravel Pit”), which was located approximately where Alden Park is today.
A 1926 aerial view of the Associated Oil Tank Farm in Tracy.
Click image for enlarged view.
The Mococo Line was fundamental to the creation of the city of Tracy, which was founded in 1878 when the nearly fifty-mile-long line was opened between Martinez and here.
Originally constructed as the San Pablo & Tulare Railroad, it was built as an extension — a shortcut, as it were — connecting the Central Pacific’s established northern line near San Pablo Bay and its line through the San Joaquin Valley via Stockton and Lathrop over the Eastbay Hills to Oakland. (The SP&T was consolidated into the Southern Pacific Railroad, the successor to the Central Pacific, in 1888.)
All that currently remains of this facility today is a group of hillocks at the corner of Tracy Blvd. and Beechnut Avenue, across from the city’s corporation yard.
Contaminated soil in the area led to a landmark court case, Cose v. Getty Oil Co., over who was responsible for waste from the tanks that had seeped into the soil surrounding the “Gravel Pit.”
ABOVE: An excerpt from a 1955 USGS map of Tracy, showing the Tank Farm area. Note that the current Tracy Boulevard, previously known as Oil Road, did not extend across the tracks here at this time.
ABOVE: A Google Earth aerial view of the Tank Farm area as it appeared in 2013. Tracy Blvd. curves from top to bottom at right, with Alden Park in the lower-left corner.
Southern Pacific Train 51, the westbound San Joaquin Daylight, roars past the Tank Farm (at right) on July 7, 1956, on its way to Martinez and Oakland by way of the Mococo Line, in this photo by E.K. Muller
(Western Railway Museum Archive)
ABOVE: A typical Associated Oil tank car. The San Francisco-based company used “Tidewater” and “Flying A” as brand names.
Special thanks to the Western Railway Museum for permission to include E.K. Muller’s majestic 1956 photograph of the San Joaquin Daylight in Tracy (Negative No. 90126) in this article.