Brief History of Oil Development in Pico Canyon


Topographic map of Pico Canyon showing the locations of the oil wells. There were almost 80 oil wells drilled in Pico Canyon, so the map is quite crowded with dots.

The blue dots are the CSO (California Star Oil Works Co.) wells. The hill containing most of them is called CSO Hill. There is also one pink dot, Star 1, that was drilled by Hardison & Stewart. CSO 4 (originally called Pico 4) is the solid red dot and was in the area of Pico Springs. Moving to the right (east), the black dots are the PCO (Pacific Coast Oil Co.) wells. The hill with most of those wells is called PCO Hill. The hill just east of that is called Christian Hill. There are two known wells (the pink dots), called Hill 1 and Hill 2, drilled by Hardison & Stewart. Hill 3 was also drilled by H & S, but it is technically on the eastern part of PCO Hill. Stewart was evidently very religious and was against any cussing by his employees, so the hill became known as Christian Hill.

The two green triangles were the location of the two jack plants, one on CSO Hill and one on PCO Hill. Odeen 1 is not shown, but would be at the end of the road in the right lower part of the map past the "2868" elevation. (Well locations were obtained from DOGGR, now CalGem, records.)


Native Americans were probably the first humans to use the petroleum from seeps in Pico Canyon.

In early January of 1865, two Mexicans, Jesus Hernandez and Ramon Perea, found an oily substance in Pico Canyon. Their story of discovery has many variations which I cover here. Their discovery became quickly known by others. However, the first claim was not filed by them but by Romulo Pico, the son of Andres Pico. On January 24, 1865, Romulo filed a preemption claim that did not include the two Mexican discoverers. A preemption claim was supposed to only be for agriculture and grazing animals, there was no way to file a petroleum claim yet. Many other men also filed preemption claims for the lands nearby in late January and February of 1865. These men would include Henry C. Wiley (Andres Pico's son-in-law), Dr. Vincent Gelcich, Andres Pico (but not in Pico Canyon), Darius Tousley, S. S. Todd (a Civil War surgeon acquaintance of Gelcich), John Moore, J.F. Burns (future sheriff of Los Angeles), J.J. Warner, and Alex Dewitt. Romulo Pico's claim greatly upset Hernandez and Perea because they were excluded. This is evident in this letter. On May 22, they filed their own preemption claim and petroleum claim (which was possible by then) and then immediately sold out to Robert S. Baker for $300.

Little, if any, work was actually done on most of the claims. The canyons were on public lands and the early (preemption) claims were not for oil or other minerals, but for farmland and grazing. However, Mother Lode gold miners had set up mining districts on public lands, which were protected by the state and federal courts. So on March 6, 1865, the Los Angeles Asphaltum and Petroleum Mining District was formed by during a miner's meeting in O.P. Robbins' house - the Beale's cut toll house (Recorded in Los Angeles County Recorder's Office Miscellaneous Records Book 1, Pages 162-163). William P. Reynolds would be elected as the first Recorder of the new mining district. Many of the early preemption claims were re-claimed as oil claims. Then, on June 24, 1865, at another miner's meeting, the San Fernando Petroleum Mining District was formed covering Rancho San Francisco (Recorded in Los Angeles County Recorder's Office Miscellaneous Records Book 1, Pages 212-214). The first recorder was Christopher Leaming. This district would recognize the claims recorded with the Los Angeles Asphaltum and Petroleum Mining District.

At Pico Springs, Stephen Peckham (1866) reported that only a basin had been excavated to collect oil as it flowed from cracks in the canyon. The flow was an estimated 20 to 25 gallons per day.

On June 1, 1866, the Los Angeles Semi-Weekly News reported that:
"There are ten springs, or rather holes, made in the shale rock, into which the oil and water is continually running from little seams and crevices in the side of the mountain. Mr. S. Lyons, the gentlemanly superintendent, tells me that it keeps him busy continually to dip the oleaginous substance from the holes; the 'modus operandi' used by Mr. Lyons (an invention of his own) to separate the oil from the water preparatory to shipment, is exceedingly primitive. At each of the holes or artificial tanks he has an ordinary barrel placed; he then dips up the oil and water promiscuously, puts it into the barrel and when the water is settled at the bottom of the barrel, which it does in about six or eight hours, he has a small tap which he takes out and the water passes out and leaves the oil in the barrel in its crude state and ready for shipment. The amount of oil procured in this way is from eight to twelve barrels per week of No. 1 green oil."
The Los Angeles Semi-Weekly News of June 1, 1866, says this about Hughes:
"Mr. Hughes, a gentleman who has the superintendence of another well, situated about one mile in an Easterly direction from the Pico Springs [this claim was near the top of PCO Hill east of Pico Springs], and upon the same strata, has been boring for the last month and has been rewarded for his perserverance and industry, after having bored to the depth of nearly two hundred feet, by having thirty-two feet of pure green oil without water. He has just received from San Francisco a large wooden tank which, when put up, will probably hold fifty barrels; he also has a large amount of iron pipe through which the oil must pass to the tank. He has suspended his work of boring and will not resume until he has a pump completed which is in course of erection. When the pump is up as well as the tank, it is his intention to pump the oil and resume boring without the fear of losing much oil in case he should strike a flowing well."
The Los Angeles Semi-Weekly News of September 21, 1866, reported that "Mr. M. F. Hughes, of the San Fernando Petroleum Co. (incorporated in July of 1865), has bored to the depth of about 200 feet, and is obtaining a constant increase of as fine oil as can be found anywhere."

The Fourth Annual Report of the State Mineralogist for 1884 states that in 1866 "Mr. Hughes bored for oil in Pico Canon, and struck a flowing well at 140 feet, but the tools became fast in the well and could not be extricated." This information was obviously taken from Peckham's 1866 report. Peckham spells the name "Hewes". Peckham places the Hughes claim east of, and 800 to 1000 feet above, Pico Springs. There is a canyon east of Pico Springs that is called Hughes Canyon on two maps that I have seen. It is a tributary of Pico Canyon and enters Pico from the south at Johnson Park. One map that shows it is in the 10th Report Of The State Mineralogist of 1890. The other map is from "Petroleum in California" by Prutzman from 1913 (see maps at bottom of this page).

200 or even 140 feet is pretty deep for a spring pole, so it's probable that Hughes used a steam engine for drilling. In fact, Los Angeles Semi-Weekly News of December 5, 1865, said that "Hughes, of the San Fernando Mining and Petroleum Company, received from San Francisco, per steamer Orizaba, two complete sets of machinery for boring oil wells. It is the intention of this company to push forward the work of boring upon two of their claims. The grounds of this company are located in the district where the crude oil is now being procured in considerable quantities from several springs." The would certainly indicate that Hughes used a steam engine for drilling his well, maybe the first in the San Fernando Petroleum District.

The Los Angeles Semi-Weekly News of July 6, 1866, states that "The San Fernando Petroleum Co., under the superintendence of Mr. F.J. Hughes, is progressing very favorably. The oil from this well is of very superior quality and it will be but a short time before the quantity will be sufficient to realize the most sanguine expectations. Mr. Hughes has just pet up a pump, the first one in this district, and hopes in a short time to show great results."

Mr. Hughes was Francis John (F.J.) Hughes. He was born in Maryland in about 1815. He died on January 13, 1868, in San Mateo, California. He probably left the Pico district because he became frustrated with his drilling tools being stuck in the bore hole and not being able to get them out.

The Fourth Report also states that on January 28, 1867 "twelve barrels of crude oil were shipped from Pico Canon." The report later says that "among the specimens from California sent to the Paris Exposition of 1867 was petroleum from ... Wiley's Spring, San Fernando Mountain (Pico Canon), Hughes' Spring, and Pico Spring, Los Angeles County."

Then, to confuse the issue, the Fourth Report then says "In 1869, the first work was done at Pico Canon by Mr. Hughes, who put down a spring-pole well called the Pico Well." This is two pages after the report said that Hughes sunk a well in 1866, not to mention that Hughes died in 1868.

According to Ripley (1948): At Pico Springs "Mr. Lyon commenced operations by driving a tunnel into the hill near the level of the stream at a point where gas and oil where escaping. He drove a distance of 20 feet and he was forced to abandon it by gas. A well was then dug to collect the seepage which averaged about two barrels a day." Other sources claim that Sanford Lyon dug a well in 1869. However, later evidence (deposition of Charles A. Mentry, R. S. Baker vs. California Star Oil Works, Case No. 4437, 17th District Court, County of Los Angeles, 1878) state that Lyon did not drill a well at this time. He probably just dug pits. Lyon did drill his well in 1876, which he mentioned in his deposition in the same case, although in another deposition, it was claimed that Lyon did not actually do the drilling but hired men to dig the well.

The Titusville (Pennsylvania) Morning Herald of October 8, 1874, from a visit on September 24, 1874, reports that only a tunnel existed. There were no wells.
"We proceed about a mile and a half further to the Pico spring, going by a wagon road to the head of the canyon. A tunnel similar to the Moon [Moore], was dug in the shale, and about thirgy gallons of petroleum was collected per day. About twenty barrels were then on hand awaiting transportation. This was the finest oil we had seen, and satisfied us beyond a doubt of its existence here. This, which had been exposed to the sun, we judged to be about twenty-five degrees gravity. An owner has since told me that it was twenty-seven degrees."
From the deposition of Charles A. Mentry given June 11, 1878:
"I first became acquainted with the premises mentioned in the complaint [the Pico Oil Springs claim] in September 1875. At this time no wells had been drilled on the same, but a few shallow or surface excavations and a little other work had been done for the purpose of catching the oil that seeped from the Pico Oil Springs.
Optimistic investers (such as Vencent Gelcich, F.P.F. Temple M.W. Childs, S.B. Caswell and others) had formed the Los Angeles Petroleum Refining Company in July of 1873 and constructed a small refinery at Lyon's Station, nine miles from Pico Canyon, in 1874. However, it was unsuccessful. No one could refiner the crude oil and the refinery was shut down.

In 1875, D.C. Scott and John G. Baker leased the Lyon's Station refinery and were able to get verbal permission from Robert S. Baker to drill at the Pico Oil Springs claim. They called their partnership the Star Oil Works and hired Charles A. Mentry, an experienced Pennsylvania oil driller. He would drill three wells for them in 1875.

From Division of Oil, Gas, and Geothermal Resources (DOGGR) records (with data they copied from the original California Star Oil Works records written by Charles A. Mentry):
CSO 1 - Commenced drilling August 22, 1875, Completed drilling September 1875 - "Well was drilled to 120 ft. with spring-pole rig. At 30 ft. produced about two bbls. per day by sand pumping. This oil was in shale. At 120 ft. pumped 10 to 12 bbls. per day. In 1877 got an engine and deepened well to 600 ft. At 175 ft. it pumped 30 bbls. per day. In 1882 deepened again to 735 ft. but without any benefit. The best sand-rock was at 170 ft."

CSO 2 - Commenced drilling Oct. 13, 1875, Completed drilling Nov. 29, 1875 - "Well was drilled to 140' with a spring pole rig. Struck first oil at 73'. At 85' pumped six barrels per day. At 140' pumped 13 barrels per day but did not pump all the time as there was not sufficient market for the oil, so well was permitted to flow about a year. Deepened with a large rig in 1877. At 250' had the best sand rock encountered and well flowed 20 to 25 bbls. per day. At 525' pumped 40 barrels per day. In 1882 deepened to 830' but no more oil."

CSO 3 - Commenced drilling December 1875 - "Well was drilled with a spring-pole rig to 170'. Got a little oil at 28'. Struck first oil at 65'. At 90' pumped 4 bbls. per day. At 145' pumped 8 bbls. per day, and at 170' 11 bbls. Well never deepened as it was too close to wells 1 and 2. After about a year-and-a-half, production dropped to a barrel a day when pumping was discontinued and rig taken down."
In 1875, Robert C. McPherson owned about 200 acres of mining claims in Pico Canyon east, and above, Pico Springs (on what is called PCO Hill today and was the old Hughes claim). In December of 1875, the San Francisco Petroleum Company was organized by McPherson and Robert C. Page. McPherson gave the claims to the company. In early 1876, a Farrar & Trefts engine was used to drill this company's first well. Unfortunately, the tools got stuck in the well and could be retrieved. The same fate also happened to their second well.

In February of 1876 with Baker's permission, Sanford Lyon (a minority owner of the Beale and Baker claim) drilled a 170 foot spring pole well near the three Mentry wells (from White, 1962). According to D.G. Scofield, Lyon was not the one who actually did the drilling. In Scofield's depostion in the previously mentioned Baker vs. California Star Oil Works case (4437) he said:
"Lyon did own the Lyon well but he did not personally drill the same and as I know has had but little to do with operating and pumping the well, the same having been done chiefly by G. W. Porter and Herbert Stanton."
From the deposition of Sanford Lyon given June 17, 1878:
"I am now, and have been for more than two years last past, operating an oil well on the Pico claim No 1. [which is the Pico Oil Springs claim]"
In March of 1876, Scott and Baker sold out to Rueben Denton. He obtained a written lease from R.S. Baker for three years to drill for oil on the Pico Springs claim. On May 3, 1876, Denton, along with new partners A.J. Bryant, mayor of San Francisco, M.L. McDonald, R.C. Page, and C. Jones, incorporated a new company called the Star Oil Works Company. Due to an impending lawsuit against Denton and the old Star Oil Works firm, they re-incorporated on June 21 under the name of the California Star Oil Works Company (CSOW). In August of 1876, Mentry started well number 4 with the first steam engine used at Pico Springs (AB Perkins, The Story of our Valley, Sept. 18, 1954, 1878 Mentry deposition). According to White (1962, p.39), an old steam rig that had once belonged to a Tom Scott Company was used. This was at least the fifth steam engine used in the San Fernando oil district. The first was apparently used by F.J. Hughes in 1866. Then, in 1874, one was used on the Temple claim in Towsley Canyon. In early 1876, McPherson used one on his well above Pico Springs. He had taken over the Hughes claim.

From DOGGR records for CSO 4 (with data they copied from the original California Star Oil Works records written by Charles A. Mentry):
"CSO 4 - Commenced drilling August 1876, Completed drilling Sept. 26, 1876 - "Caved badly at 270'. First oil at 250' in shale. Tubed and pumped at 370', producing 25 barrels daily for some time. In August, 1877, commenced to deepen well. At 560' the well was flowing 70 barrels daily, and was still flowing in April, 1879 when it was rigged for pumping. In 1885 it was deepened from 610 to 1030' but it is thought the only good attained was in consequence of cleaning it out."
CSO 4 would became, according to Standard Oil, the first commercially successful oil well west of Pennsylvania.

In September of 1876, CSOW became a target of San Francisco oil merchants Frederick B. Taylor and his junior partner Demetrius G. Scofield. They had visited the San Fernando oil district earlier in 1876 and were pleased with what they saw. So Taylor bought a 30% interest in the company and both men joined the Board of Directors, becoming the main decision-makers of CSOW. Taylor became the General Manager and Scofield his advisor and field man. Taylor secured 3/7 rights to Pico Springs equaling the percentages of Baker and Beale. He also acquired hundreds of acres of undeveloped claims in Pico Canyon.

In 1877, CSOW built a new refinery near Andrew's Station close to the newly completed Southern Pacific railroad. Joseph A. Scott, the Lyon's Station refiner, supervised its construction. From there, the oil could be refined and shipped to San Francisco, where the demand for oil was.

Scofield realized that the CSOW was under-capitalized. He was able to interest Senator Charles N. Felton, Lloyd Tevis, and others, into forming a new company. On February 19, 1879, the Pacific Coast Oil Company (PCO) was formed with Felton as the president and Scofield as the vice-president. It was re-incorporated on June 21, 1879 At first, they began drilling on the claims (called Menlo and Belmont) just east of the Pico claim. Felton had evidently purchased the San Francisco Petroleum Company's claims sometime in 1879. A court battle began (starting on March 22, 1878 and ending on June 28, 1879) between CSOW (and later PCO) versus Pico claim holders Beale and Baker. Beale and Baker claimed that CSOW violated the terms of their lease by failing to operate the company in a workmanlike manner. The case was not really won by either side, but there was a mutual agreement that CSOW would be divided with PCO owning 4/7 of CSOW and Beale and Baker owning 3/7. Since there would still be two separate companies (and Beale and Baker were entitled to CSOW profits), the well numbering was separate. Hence there were both CSO wells and PCO wells. In fact, before 1883 the PCO wells were either named "San Fernando" or "San Francisco Petroleum" and were later changed to PCO numbers.


In 1879, California's first oil pipeline, 2-inches in diameter and about 7 miles long, was laid from Pico Canyon to the refinery. Oil flowed by gravity and partly by pumping (Scientific Amerian Supplement No. 610, 9/10/1887). The pipeline was also used to carry water, using a pump, to the canyon until the end of 1881 (White, 1962, p.80), when a new 4 mile long pipeline was laid for water from the Santa Clara River northwest of Pico Canyon. At the same time, a 1300 barrel water tank was built on the "rim" of the canyon where water could be distributed to the area. As more wells were being drilled, more water was needed for the steam boilers that generated the power well engines. Eventually, natural gas from the wells themselves was used to power the most of engines.

In 1880, PCO built a new, larger capacity refinery at Alameda in the San Francisco area. Both the Newhall and Alameda refineries were used. The Newhall refinery was finally shut down in 1888 or 1890.

In 1883 the Hardison and Stewart Oil Company leased land (actually the lease was never executed) from PCO east of the existing wells and drilled three wells, only one of which (Hill 3) produced any oil (see part of the DOGGR well record at the bottom of this page). However, in 1887 it was ruined by water breaking in. In 1884, getting another chance with another lease from PCO, they drilled Star No. 1, located on CSO Hill above CSO 5. The location required the construction of a bridge 105 feet long and 45 feet high - the "Long Bridge." The first oil flowed on November 26, 1884 and became very successful. In February of 1885, Hardison and Stewart agreed to $1.50 a barrel for the Star and one Hill well from PCO. However, they never drilled in the Pico oil district again. They keep their interest in these two wells until February 1, 1889, when well records show that CSOW bought them out. Reportedly, they were in need of cash ("Oil, Land and Politics, Vol. II", Hutchinson, University of Oklahoma Press, 1965, p. 16). Wallace Hardison and Lyman Stewart would move to Santa Paula, join up with Thomas Bard, and later form the Union Oil Company in 1890.

The well records (from the Division of Oil, Gas, and Geothermal) show that on August 11, 1889, PCO 17 was started using the first diamond bit in California. The Western Prospecting Co. of Denver was contracted to drill at $3.50 a foot. Unfortunately, at 60 feet the hole they could not continue. The diamond bit could not handle the cobbles in the surface formation and the well had to be completed with cable-tools. On September 23, 1889, the Western Prospecting Co. tried their diamond bit again on CSO 19 and completed the well on November 30. However, the production of about 6 bpd was not good enough. Evidently the shale drillings were being forced by water pressure (which was being constantly pumped into the well for the diamond drill method) into the oil sands cementing the sand. After re-drilling with cable-tools, production rose to about 21 bpd. The Catalogue of the State Museum of California reports that they received the core of a diamond drill from Well No. 19 in Pico Canyon on October 14, 1889. In 1892, CSO 21 was straightened using the diamond drill at 765 feet.

The well records also show that there were a lot of problems with crooked holes. These were caused by the steep dip of the Pico anticline. The drill bits would tend to follow the dip of the beds. Sometimes the whole cable-tool string (which could be 20 to 40 feet in length) would get stuck in the hole and would have to be "fished" out. Sometimes the tools could not be retrieved and the hole would have to be abandoned. There were also a lot of problems with cave-ins and water flooding the hole. In January of 1888, the drilling of PCO 9 was interrupted for 15 days due to a landslide. In 1897, while pulling the casing from the hole of CSO 26, somehow the rig caught fire and burned down. In 1892, while drilling CSO 22, gas ignited at the boiler, burned down the rig, and badly burned many men. On July 25, 1940, a brush fire burned down 10 old wooden derricks (PCO 2, 13, 17, 18, 19, 24, 25, 29, 34, and 36).

The development of Pico Canyon continued on. By the end of 1884, the boundary limits to the Pico field had been established. Under Mentry, about 70 wells were drilled between 1876 and 1900 (the year of his death).


In December of 1893, PCO paid the widow of Dr. Gelcich (1828-1885) $7000 for a quitclaim to any rights he still had for his Pico claims. They were evidently still a little nervous about their ownership of the claim.

In December of 1900, Standard Oil (New Jersey) bought Pacific Coast Oil Company for about $761,000. In 1901, PCO bought out CSOW and eliminated them as a company. This allowed them to totally take over the Pico claim. In 1906, PCO and Standard Oil (Iowa) were consolidated and on July 23 their names were changed to Standard Oil (California). On November 15, 1906, the US Government filed suit under the Sherman Antitrust Act against Standard Oil (New Jersey), its subsidiaries (which included Standard Oil of California) and affiliates, and John D. Rockefeller. After a long court battle, on May 15, 1911, the US Supreme Court ruled in favor of the government and ordered the breakup of Standard Oil. In December of 1911, Standard Oil of California became a separate company. In 1977, Standard Oil changed their name to Chevron. In 2001, they became ChevronTexaco, but in 2005 they dropped the Texaco and again became Chevron.

By 1910, development in Pico Canyon was virtually done. From 1876 to 1910, 79 wells had been drilled. From 1910 to 1960, 12 wells were drilled. After 1960, 8 wells were drilled. In May of 1940, Standard Oil of California officially shut down most of its operations in Pico, Towsley, and Wiley Canyons.

The shutdown ended in 1944, with Standard drilling PCO 42 near the axis of the Pico anticline in the eastern part of the field to a depth of 8258 feet with poor results. In 1948, CSO 101 was drilled (why they skipped CSO 33 - CSO 100 I don't know). In the 1960's, CSO 102, 103, 105, 106, and 107 were drilled, mostly as part of an unsuccessful water injection program. In 1969, CSO 108 was the last well drilled in Pico Canyon.

After Mentry's death in 1900, Walton Young took over as superintendent until 1927. From 1927 - 1937 Charles Sitzman was the superintendent. After Sitzman, John Blaney took over for one year. After Blaney, there were no more superintendents, only foremen or caretakers.

The last production of CSO 4 was 1 bpd in 1989, after a "world record" of 113 years of production. However, during the war years of 1940-1944, the Pico field was totally shut down, so 113 years is not valid. In February of 1990, CSO 4 was officially plugged and abandoned. So as to not affect the well's status as a National Historic Landmark, Chevron received special permission from DOGGR to leave pipes on the surface at the wellhead, although the pump was removed. See the CSO 4 Area webpage for photos.

The best year for Pico Canyon was 1933 when production was 23,600 barrels of oil.

In 1995, Chevron sold over 3000 acres to the Santa Monica Mountains Conservancy. This included portions of Pico, Towsley, Wiley, Leaming, Rice, and East canyons. All the Pico property was sold including CSO 4 and Mentryville.


A note on well names: I am trying to stick to the last name of the well. The original wells in the Pico claim were named "Pico", for example Pico 4. About 1902, when PCO (the new Standard Oil NJ subsidiary) took over, the "Pico" name was changed to "CSOW". Sometime in the early 1960's the name was shorted to "CSO" by Standard Oil.



Map of Pico Canyon oil field (from Geology and Oil Resources of a part of Los Angeles and Ventura Counties, California, William S. W. Kew, Bulletin 753, United States Geological Survey, 1924, p. 145).



Pico Canyon Claims (from California Oil Fields, Summary of Operations, "Newhall Oil Field," Wallings, Division of Oil and Gas, Vol. 20, No. 2, 1934). The Pico Oil Spring Mine was patented on April 19, 1880 to Robert S. Baker and E. F. Beale. The Menlo Oil Mine was patented on October 8, 1890 to Occidental Asphalt Company. The Belmont Oil Mine was also patented on October 8, 1890 to Occidental Asphalt Company. Occidental Asphalt was a company incorporated in Nevada in June of 1883 by Charles N. Felton (the president of PCO) and Lloyd Tevis (one of PCO's co-founders). For some reason they did not want to use PCO directly to patent the claims.

A note on patents: A patented claim is one for which the federal government has issued a land deed (or patent. The owner of a claim must prove to the federal government that the claim contains locatable minerals that can be extracted at a profit. A patented claim can be used for any purpose by the new owner. With a patented claim you own the land as well as the minerals. Since October 1, 1994, the BLM has been prohibited by Acts of Congress from accepting any new mineral patent applications.



This clipping from the Los Angeles Herald of June 14, 1892, disagrees with Wallings' patent dates (assuming the newspaper date is close to the patent date). Here the Belmont, Menlo, Arcadia, and Camulos claims were patented to the Occidental Asphalt Company and then sold to the Pacific Coast Oil Company for nominal fees.



Table of the wells drilled in Pico Canyon:

(Primarily from Walling, 1934. Some from DOGGR records)
Last well No. Drilled By Original Well No. Year Drilled Original/max depth(ft) Initial Prod. (bpd) Remarks
C.S.O. 1 California Star Oil Works Pico 1 1875 120/735 10-12 At 175ft flowed 30 bpd
C.S.O. 2 California Star Oil Works Pico 2 1875 140/830 13 No oil below 525ft
C.S.O. 3 California Star Oil Works Pico 3 1875 170/170 11 11 bpd at 170ft. Never deepened, too close to 1 and 2. Production dropped to 1bpd, rig taken down in 1877.
C.S.O. 4 California Star Oil Works Pico 4 1876 370/1400 25 At 560ft flowed 70 bpd
C.S.O. 5 California Star Oil Works Pico 5 1880 1106/1450 ? 1887 pumped 25 bpd. In 1893 used diamond drill to try to straighten out the hole.
C.S.O. 6 California Star Oil Works Pico 6 1880 1050/1605 ? 1887 pumped 25 bpd
C.S.O. 7 California Star Oil Works Pico 7 1881-82 850/1696 ? At 250' flowed 40 bpd
C.S.O. 8 California Star Oil Works Pico 8 1883-84 1090/1090 10 3 holes drilled
C.S.O. 9 California Star Oil Works Pico 9 1882 1555/1565 ? 1887 pumped 35 bpd
C.S.O. 10 California Star Oil Works Pico 10 1882-83 975/975   Junked with tools
C.S.O. 11 California Star Oil Works Pico 11 1882-83 1450/1450   Pumped 150-200 bpd water
C.S.O. 12 California Star Oil Works Pico 12 1883 1110/1400 ? Pumped 85 barrels first 24 hrs
C.S.O. 13 California Star Oil Works Pico 13 1883-84 1500/1759 80 1887 pumped 40 bpd
C.S.O. 14 California Star Oil Works Pico 14 1883-84 1500/1500   Abandoned while drilling
C.S.O. 15 California Star Oil Works Pico 15 1888 1590/1850 ? No record of production
C.S.O. 16 California Star Oil Works Pico 16 1888-89 940/940 ? Never produced - Abandoned
C.S.O. 17 California Star Oil Works Pico 17 1889 830/830   Junked and abandoned
C.S.O. 18 California Star Oil Works Pico 18 1889 1128/1545 ? 1917 producing 3 bpd
C.S.O. 19 California Star Oil Works Pico 19 1889-90 800/890 20 First well in CA drilled with diamond drill method. 1890 producing 15 bpd
C.S.O. 20 California Star Oil Works Pico 20 1891-92 1465/1465   Junked, edge well
C.S.O. 20A California Star Oil Works Pico 20A 1892-93 1730/1730   Junked, edge well
C.S.O. 21 California Star Oil Works Pico 21 1892 1525/1730 33 Little water encountered while drilling
C.S.O. 22 California Star Oil Works Pico 22 1892 1490/1860 58 1917 producing 10 bpd
C.S.O. 23 California Star Oil Works Pico 23 1892-94 1525/1525 16 1917 produced 2.5 bpd
C.S.O. 24 California Star Oil Works Pico 24 1896 1605/2045 ? 1917 produced 3.6 bpd
C.S.O. 25 California Star Oil Works Pico 25 1896-97 1500/1500 ? Pumped 70 barrels first day
C.S.O. 26 California Star Oil Works Pico 26 1897-99 1630/1630   Junked, edge well
C.S.O. 27 California Star Oil Works Pico 27 1898 1010/1010 ? 1917 produced 1 bpd
C.S.O. 28 California Star Oil Works Pico 28 1898 1320/1320 ? 1917 produced 2 pbd
C.S.O. 29 California Star Oil Works Pico 29 1898-99 1155/1155 ? 1917 produced 1 bpd
C.S.O. 30 California Star Oil Works Pico 30 1899 1060/1060   Abandoned while drilling
C.S.O. 31 California Star Oil Works Pico 31 1899 1240/1240 ? No record of any water while drilling
C.S.O. 32 California Star Oil Works Pico 32 1903-05 3090/3445 ? 1917 pumped 10 bpd. Converted to waste water disposal well in 1960. Abandoned in 1967.
C.S.O. 101 Standard Oil Co C.S.O. 101 1948 2068 ? Abandoned 1990; 8/89 produced 9bpd
C.S.O. 102 Standard Oil Co C.S.O. 102 1960 2400 ? Abandoned 1990; 1965 converted to water injection well
C.S.O. 103 Standard Oil Co C.S.O. 103 1963 1888 ? Abandoned 1980; 1965 converted to water injection well
C.S.O. 104 Standard Oil Co C.S.O. 104 ? ? ? No records at DOGGR
C.S.O. 105 Standard Oil Co C.S.O. 105 1965 1622 ? Abandoned 1990; 1966 converted to water injection well
C.S.O. 106 Standard Oil Co C.S.O. 106 1965 1750 ? Last production 1 bpd in 1986. Abandoned in 1990
C.S.O. 107 Standard Oil Co C.S.O. 107 1965 1900 ? Last production 1 bpd 1989. Abandoned in 1990
C.S.O. 108 Standard Oil Co C.S.O. 108 1969 2195 ? Abandoned in 1980
Star 1 Hardison & Stewart Star 1 1884-85 1650/1680 35 1887 pumped 30 bpd
Simi 1 California Star Oil Works Simi 1 1883-84 1300/1300   Outpost well, abandoned while drilling
Newhall Land & Farming 1 Standard Oil Co. of Ca.   1907-08 1750/1750   Outpost well, abandoned while drilling
P.C.O. 1 Pacific Coast Oil San Fernando 1 1881-82 1176/1695 ? 1887 pumped 20 bpd
P.C.O. 2 Pacific Coast Oil San Fernando 2 1882 1280/1280 ? 1887 pumped 40 bpd
P.C.O. 3 Pacific Coast Oil San Fernando 3 1882-83 1386/1870 ? 1887 pumped 25 bpd
P.C.O. 4 Pacific Coast Oil San Fernando 4 1882-83 1400/1910 ? 1887 pumped 18 bpd
P.C.O. 5 Pacific Coast Oil San Fernando 5 1882-83 1510/1510 ? 1887 pumped 18 bpd
P.C.O. 6 Pacific Coast Oil San Fernando 6 1883-85 2330/2330 ? 1887 pumped 10 bpd
P.C.O. 7 Pacific Coast Oil San Fernando 7 1882-83 1880/1880 ? Abandoned while drilling
P.C.O. 8 Pacific Coast Oil San Fernando 8 1886-87 1345/1408 ? 1887 pumped 60 bpd
P.C.O. 9 Pacific Coast Oil San Fernando 9 1887-88 1065/1330 ? No record of production
P.C.O. 10 Pacific Coast Oil San Francisco Pet 1   840/840 ? No records
P.C.O. 11 Pacific Coast Oil San Francisco Pet 2 1881 1515/1515 ? 1887 pumped 5 bpd
P.C.O. 12 Pacific Coast Oil San Francisco Pet 3 1882-83 1360/1360   Abandoned while drilling
P.C.O. 13 Pacific Coast Oil San Francisco Pet 4 1883 1545/1700 ? 1887 pumped 40 bpd
P.C.O. 14 Pacific Coast Oil 14 1888 975/1530 50 1890 pumped 15 bpd
P.C.O. 15 Pacific Coast Oil 15 1889 1220/1220   Abandoned, could not shut off water
P.C.O. 16 Pacific Coast Oil 16 1889?     I found site. Looks like it was abandoned without finding oil.
P.C.O. 17 Pacific Coast Oil 17 1889-90 840/1523 ? 1917 pumped 1.6 bpd
P.C.O. 18 Pacific Coast Oil 18 1890 1200/1770 50 1893 pumped 8.5 bpd
P.C.O. 19 Pacific Coast Oil 19 1890 640/1325 ? 1917 pumped 2 bpd
P.C.O. 20 Pacific Coast Oil 20 1890 495/495 ? No record of production
P.C.O. 21 Pacific Coast Oil 21 1890 1055/1715 ? No record of production
P.C.O. 22 Pacific Coast Oil 22 1890 1575/1935 ? No record of production
P.C.O. 23 Pacific Coast Oil 23 1896-97 1810/1810 ? 1917 pumped 6 bpd
P.C.O. 24 Pacific Coast Oil 24 1890-91 1050/1550 ? 1917 pumped 3 bpd
P.C.O. 25 Pacific Coast Oil 25 1891 1195/1610 60 1893 pumped 14.5 bpd
P.C.O. 26 Pacific Coast Oil 26 1891 943/943   Abandoned, could not shut off water
P.C.O. 27 Pacific Coast Oil 27       No records
P.C.O. 28 Pacific Coast Oil 28 1892-93 1610/1610 88 1893 pumped 32 bpd
P.C.O. 29 Pacific Coast Oil 29 1892 1555/1555 ? 1917 pumped 4.7 bpd
P.C.O. 30 Pacific Coast Oil 30 1895 1165/1165   Abandoned, could not shut off water
P.C.O. 31 Pacific Coast Oil 31 1892-93 1200/1650 ? Abandoned
P.C.O. 32 Pacific Coast Oil 32 1894-95 1600/1600   Abandoned
P.C.O. 33 Pacific Coast Oil 33 1899 1135/1135   Abandoned while drilling
P.C.O. 34 Pacific Coast Oil 34 1899-1900 1912/1912 ? 1917 pumped 3 bpd
P.C.O. 35 Pacific Coast Oil 35 1900-01 1190/1190 ? 1917 pumped 3 bpd
P.C.O. 36 Pacific Coast Oil 36 1901-02 1419/1419 ? 1917 pumped 1.6 bpd
P.C.O. 37 Standard Oil Co 37 1907 1950/1950 ? No record of production
P.C.O. 38 Standard Oil Co 38       No records
P.C.O. 39 Standard Oil Co 39 1909-10 1425/1580 ? 1917 pumped 4.5 bpd
P.C.O. 40 Standard Oil Co 40 1909 1128/1128   Abandoned while drilling
P.C.O. 41 Standard Oil Co 41 1916 2201/2201 ? 1917 pumped 16.5 bpd
P.C.O. 42 Standard Oil Co 42 1944 8258 ? Abandoned 1984 - never produced
P.C.O. 43 Standard Oil Co 43 1965 2000 ? Abandoned 1985
Hill 1 Hardison & Stewart Hill 1 1883 1850/1850   No oil, lost tools, abandoned
Hill 2 Hardison & Stewart Hill 2 1883-84 1050/1050   Lost tools and abandoned
Hill 3 Hardison & Stewart Hill 3 1884 1550/1550 5 Meager production. In 1887 water broke in killing production.
Odeen 1 Union Oil Company 1 1951-52 9215/9215 0 Abandoned 1953 - never produced


This is part of a map by Edward North called "Oil Fields in Pico Canyon" from the "Tenth Annual Report of the State Mineralogist for the Year Ending December 1, 1890" by the California State Mining Bureau. It shows Hughes Canyon. See here for the complete map in PDF form (3.3 MB).


The previous North map was clarified by an unknown person (possibly Everette DeGolyer) at an unknown time. There were actually two maps that I pasted together. They were found in The Everette Lee DeGolyer, Sr. papers, Accession No: Mss 0060 and Mss 0060x, Southern Methodist University DeGolyer Library. See here for a larger version.


This map showing the Pico, Menlo, and Belmont claims is from Petroleum in Southern California, California State Mining Bureau Bulletin 63, 1913, by Paul Prutzman. CSO 4 is in red rectangle. The tributary canyon that flows into Pico Canyon at Johnson Park is called Hughes Canyon (underlined in red). The letters were used as endpoints in cross section maps. See here for the PDF of the Pico Canyon section in the bulletin.


From the Oakland Tribune of 11-4-1918 comes support for the del Valle account of the discovery of oil.



Pico Canyon visitor account from 1884 (Scientific American Supplement, Vol. XVII, No. 430, March 29, 1884, p. 6870)



Here is a model spring pole rig from the Petroleum Age magazine of March 1920. The first three Pico wells were drilled using a spring pole. This model looks like one shown in the historic photos page for either Pico 3 or the Sanford Lyon well.

Hemlock (or Hickory) Engine - (Spring Pole method) A primitive method in which a small hemlock tree would be bent over and held there by a yoke. Then two men would throw their weight into stirrups, driving the bit down (or easing the tension to let it fall) and then letting the spring of the sapling pull up again. Such a rig was derisively call a "hemlock engine".

For more information on spring pole rigs, here is a report from the School Of Mines Quarterly of November, 1894, entitled "Spring-Pole Drilling" by Edgar Tuttle.



Two pages from the DOGGR well records for the Star 1 well