CSO 4 Area


CSO 4 was originally named Pico 4 and then CSOW 4 (for the California Star Oil Works). It was completed in September of 1876 by Charles Alexander Mentry and became the first commercially successful oil well in the world. It was shut down in 1989 (with production at 1 bpd) after producing oil for 113 years, the longest run of any commercial oil well in the world. It was officially abandoned in February of 1990. (Note: The oldest producing oil well in the world is the McClintock No. 1 in Rouseville, PA. It has produced oil every year since 1861. However, it did not not commercially produce oil all those years. Since the early 1950's it was pumped only a few times a year just to retain its "oldest producing title." See here for more information on this well.)

When you reach the CSO 4 well site, you see all the old jackplant equipment, a steam engine, some pipes marking the actual well head, and two markers. The road from Mentryville to the hairpin curve was resurfaced in 2011.

After you pass CSO 4, you reach the machine shop area which covered much of the hairpin curve area.


The following photos were taken when the engine and power were on on the left side of the road before you reach CSO 4. At that time, the well was past the equipment on the right where the marker is barely visible. The bottom of CSO Hill is to the right of the hiker. That's my black backpack in the middle of the road.


The engine is on the left and the power is on the right


Both from the opposite direction


This appears to be a gas engine. The actual builder's name is missing. The white stamped on Standard Oil serial number is 52207. There are also two manufacturer serial numbers 25C55 and 25C64 on two different parts of the engine. Walling (1934) reports that all the jack lines were powered by gas engines.


Meese & Gottfried Company, S F Cal. They are the manufacturer of the pulley, but not of the complete engine.


Pat Oct 23 1900, No 5


From 1916 Meese & Gottfried catalog



The belt around the pulley on the right was about 1 ft wide


This is a large jackline hook


Here is a broken up and burned "power" or "central power unit". The place where this was set up was called a jack plant or pump house.


This 64-inch diameter large wheel would be mounted vertically. The belt would attach over it. The belt (powered from the engine) would turn the wheel around and around.


This picture of the same wheel shows the geared smaller wheel on the other end of the shaft


The 4-foot diameter geared wheel shown here would be mounted with the gears facing the ground. The smaller geared wheel from the previous wheel would fit into the gears on this wheel. The shaft for this wheel would be vertical and attach to the shaft of the next photo with the eccentric.


Hear is the shaft cut off on the bottom with the eccentric wheel on the top. The large geared wheel just above and to the right was the piece cut off from it. When they were in one piece, the power was at least 10 feet high.


Hear is the shaft support. This would have large pieces of wood and metal cables attached to it to support the shaft.


On top of the support is "Baker Iron Works"


This is the eccentric with a 30-inch diameter eccentric plate. As the large geared wheel on the bottom of the shaft turned, the eccentric wheel turned. The plate on top would not be attached to the eccentric wheel and so could rotate indepently from the wheel. As the eccentric wheel rotated, the plate would be able to remain relatively motionless so that the jacklines attached to it would not get tangled up. However, the plate would travel in a circular path. Based on the 1962 newspaper article shown below, there was another eccentric wheel attached to the same shaft as this one.


This is the other end of the eccentric wheel. It would face the sky. You can see about 24 openings in the plate where jacklines could be attached. The jacklines would then be attached to a jack pump (like the one at the replica rig in Johnson Park) at a distant well. Because the eccentric is not a perfect circle, the jacklines would be pulled and pushed a certain distant as the eccentric rotated. This pulling and pushing would cause the jack pump at the well to move up and down, causing the oil to be sucked out of the well. The jacklines could either be solid, like a sucker rod, or steel cables. If a cable, there would be a counterweight at the jack pump to help pull the cable back from the jack plant. The thing on top is an oil cup. It would have been turned up 90 degrees from its present position and would hold oil which would lubricate the wheel. See the Elsmere Canyon jack plant page for more information. The unit there is almost exactly like this one, except it is missing the eccentric plate on top.


Here is a close-up of one of the holes in the eccentric wheel showing a lot of wear. There was definitely a jackline connector here for a long time.


This device was probably a cable stretcher. The distance from the engine to the power could be 30-40 feet. The actual length of the cable was more than twice that distance.


Before it was moved to the well site, the equipment was all shoved next to the engine




Here is the equipment at the well site in March of 2012. Besides being repaved, the road has been improved here.


A picture of probably this jack plant is shown in a Daily Signal article from 1962 - "Pico Ghost Camp" - by A.B. Perkins (part 2, 1/25/62). It is obviously hard to see here but you can see two eccentrics. Perkins states that this plant powered CSO wells and the lower picture shows the jacklines coming to the road below. The plant must have been in the same area where the current ruined plant is, so I'm guessing that it is the same plant as is in the newspaper picture.


Here are the two markers at the CSO 4 well site. The pipes between them mark the location of the actual well head.


Closer view of the well head


Darryl Manzer and his sister Karen at the well. They were residents of the canyon from 1960-66 and their dad Al had had a lot to do with the well becoming a National Historic Landmark. (Picture taken 10-16-2008.)


Well No. 4
Pico Canyon Oil Field

Has been designated a
registered National
Historic Landmark

Under the provisions of the
Historic Sites Act of August 21, 1935
this site possesses exceptional value
in commemorating or illustrating
the history of the United States

U.S. Department of the Interior
National Park Service

1966


First Commercial Oil Well
In California

On this site stands CSO-4 (Pico #4) California's
first commercially productive well. It was
spudded in early 1876 under the direction
of Demetrius C. 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 deep-
ened 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 seventy-seven years.

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.

Dedicated June 6, 1953
Standard Oil Company of California
Petroleum Production Pioneers, Inc.

State Registered


Still pumping away in 1961. Note that there is a base to the monument which is now buried. Also note that the pump appears to be the same pump that had been dumped on the grounds of Johnson Park.


Letter from Chevron to DOGGR about the abandonment of CSO 4. For a normal well abandonment, the well is capped below the ground surface, but for CSO 4 Chevron got that requirement waived so as to not jeopardize the status of the well as a National Historic Landmark. That's why you can see the wellhead and some other pipes at the site.


Letter from the National Park Service to Chevron