At the end of the first boom, 75 companies had drilled 60 wells in California, spending $1 million to produce $60,000 worth of oil.

[9] Oil seep locations in present-day Pico Canyon area of the northern Santa Susana Mountains were known and used for centuries by the local Tataviam and Tongva Native Americans for medicinal and healing purposes.

Various accounts exist about the Spanish-Mexican era rediscovery by non-indigenous people of oil in Pico Canyon.

The quality of the oil in the spring attracted his attention, being of a dark, green color and very thin, and so different from anything that he had ever seen, that he concluded it must be valuable.

[11] Yet another account indicates that Perea brought a small amount of the curious substance to the Mission San Fernando, where a Dr. Gelsich recognized it as petroleum and at once formed a company to stake out claims.

4 in July 1876 and struck oil on September 26, 1876, at a depth of 370 feet (110 m); the well immediately began producing 25 barrels per day (4.0 m3/d).

4 was drilled with great difficulty since "the railroad had not then been completed, there was no road into the canyon, water was almost unattainable, and there were no adequate tools or machinery to be had.

"[14] Mentry used his mechanical skills to create improvised tools, including a drill-stem he built out of old railroad car axles, which he purchased from the Southern Pacific and welded together.

[13] When Mentry drilled the well to a depth of 560 feet (170 m) in 1877, the oil spurted to the top of the 65-foot (20 m) derrick,[9] increasing the production to 150 barrels per day (24 m3/d).

[21] In 1882, the editor of the fledgling Los Angeles Times traveled on horseback to see the celebrated Pico Canyon oil wells.

When Mentry died, the entire town of more than 200 persons,[8][27] except for three individuals left behind in Mentryville, traveled to Los Angeles for his funeral, bringing with them a large floral arrangement in the shape of an oil derrick.

A visitor to the camp that year reported that "rusted oil equipment cluttered the canyon," toppled derricks lay rotting, and the cemetery was "choked with weeds, hidden and forgotten.

[28] A group called the Friends of Mentryville was organized to restore the buildings and open the old town as a historic park.

It was not only the discovery well of the Newhall Field, but was a powerful stimulus to the subsequent development of the California petroleum industry.