One of Chevron's early predecessors, Star Oil, discovered oil at the Pico Canyon Oilfield in the Santa Susana Mountains north of Los Angeles in 1876. The 25 barrels of oil per day well marked the discovery of the Newhall Field, and is considered by geophysicist Marius Vassiliou as the beginning of the modern oil industry in California. Energy analyst Antonia Juhasz has said that while Star Oil's founders were influential in establishing an oil industry in California, Union Mattole Company discovered oil in the state eleven years prior.