#0516 Well No. "CSO" 4 (Pico No. 4)


#0516 Well No. "CSO" 4 (Pico No. 4)

Site information:

On W Pico Canyon Rd, 1.5 mi past Mentryville, Newhall

The road is usually gated to cars at Mentryville, but can be hiked or biked.


Plaque information:

Private plaque

Plaque text:

First Commercial Oil Well in California

On this site stands CSO-4 (Pico No. 4), California's first commercially productive well. It was spudded in early 1876 under the direction of Demetrious G. Scofield, later to become the first president of Standard Oil Company of California, and was completed at a depth of 300 feet on September 26, 1876, for an initial flow of 30 barrels of oil a day.

Later in the same year, after the well was deepened to 600 feet using what was perhaps the first steam rig employed in oil well drilling in California. Upon the second completion it produced at a rate of 150 barrels a day - it is still producing after 77 years.

The success of this well prompted formation of the Pacific Coast Oil Company, a predecessor of Standard Oil Company of California, and led to the construction of the state's first refinery nearby. It was not only the discovery well of the Newhall Field, but was indeed a powerful stimulus to the subsequent development of the California petroleum industry.

Dedicated June 6, 1953.  Standard Oil Company of California, Petroleum Production Pioneers, Inc.