This site is on the northern edge of the West Coyote oil field, one of the largest fields in the Los Angeles Basin. This field produced about 250 million barrels of oil from sandstone at a depth of about 3,000'. West Coyote was active from 1903 to 1996, and it was one of the foundations of the oil industry in Southern California. This field played a significant role in the early history of both the city of La Habra and of Chevron Corporation.
On the flat land south of here Chevron operated its La Habra Research Laboratory from 1947-1999. The personnel who worked here made a number of important contributions to mankind's knowledge of geophysics, oil field recovery processes, geology, and engineering, and they brought international scientific recognition to La Habra.
This rock is diatomaceous shale from the Miocene Monterey Formation, collected near San Luis Obispo. The Monterey is one of the most important formations to California's petroleum industry. It is rich in organic material and therefore a source of petroleum and, where fractured (as in this example), is a good reservoir. Oil and gas fields associated with this formation occur both onshore and offshore in California.