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

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 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, the well was deepened to 600 feet, using what was perhaps the first steam rig employed in oil well drilling in California. Upon this second completion, it produced at a rate of 150 barrels a day, and is still producing after 77 years (1953). 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.