Coquina Mine

In 1935 Coquina Mine's operations ceased, but it was impossible to recover large equipment due to washouts along the road.
This P&H Model 206 Power Shovel wasabandoned after mining operations ceased in the 1935.


County: Ventura
Primary Mineral: Limestone was mined here for an extremely pure form of Calcium Carbonate (Calcite CaCO3) 

Years of Operation: 1929-1935 When mining operations ceased, the road used to bring in equipment had been largely washed away and much of the mining equipment was left behind.

Nearest City or Landmark: Simi Valley, Las Llajas Canyon.

Depth: This was a strip mining operation so there are no shafts or adits

The Model 206 put the P&H Mining Equipment on the map. They would later go bankrupt, due to asbestos lawsuits.
This dipper could lift 500 pounds. The P&H Model 206 was considered a small power shovel.

History of the Coquina MIne

In the hills above Simi Valley lies a largely forgotten mining operation called the Coquina Mine, high in the hills above Las Llajas Canyon. In the early 1900s this land was owned by the Simi Valley Oil Company, and was later purchased by Howard Marr in the 1920s. It became known as  Marrland, and today much of it is still known as Marrland Open Space. In 1929 Howard Marr leased a portion of his land to the Tapo Alto Shell and Fertilizer Company to mine for limestone. 

Here’s an excerpt from a book written in the early 1900s by Clarence A. Logan called Limestone in California: 

”During the last twenty years there has been irregular production from deposits of shell limestone on rancho Simi, north and east of north from Santa Susana. The quarries are on hills 2.5 miles apart and 1 to 2 miles from the Los Angeles County line.” 

This would indicate there is another mine that I have yet to locate (possibly the Tapo Gillibrand Mine), but for now I’ll just cover the Coquina Mine.

The Coquina MIne closed in 1935. Much of its heavy equipment was abandoned at the site.
This was a strip mine, so you won't find any shafts or adits, but there are artifacts galore. 


In 1929 heavy equipment was brought in to strip the hilltop of an unusually pure form of Calcium Carbonate (Calcite CaCO3) from a fossilized reef called "Coquina Limestone" (Shell or Oyster Limestone). The State Department of Agriculture found it to be 98% pure. At one time this entire area was under the sea, and you can see evidence of this in the thousands of shells embedded in the rock near the mine. You might wonder why anyone would mine for limestone. Apparently is was crushed and used as poultry grit, cattle feed and for other agricultural needs. This was a six year mining operation which lasted until 1935, but during or after that time heavy rains and landslides washed away much of the mining road, leaving a huge power shovel stranded at the top of a mountain. And that’s where is sits today, abandoned and nearly forgotten, along with a lot of other equipment. Most of the shells you find in this area came from oysters and scallops, which are said to have rested in very shallow water.  

One artifact at Coquina Mine has patent stamps dating back to the late 1800s.
One of the larger artifacts has patent stamps dating all the way back to the late 1800s.

P&H Mining Equipment

The Coquina Mine (or quarry) was a strip mining operation, so you won’t find any shafts or adits there, but the main attraction is an old P&H Company power shovel (seen in the first two photos), still fully intact, despite the efforts of some jackass who decided to paint some of its parts. This is an old Model 206, considered to be a small power shovel. But this was the product that put the P&H Company on the map. The colors you see painted on the caterpillars and gears are not original. This equipment was vandalized by some idiot who thought he was being artistic. 

The colors on this power shovel are vandalism. It's the reason I don't reveal mine locations.

P&H Mining Equipment was founded in 1884, when Alonzo Pawling and Henry Harnischfeger started a small machine and pattern shop to make components and assemblies for industrial equipment needed in the Milwaukee area. Their first creation was an overhead traveling bridge crane for use in factories. But the economy slowed and Pawling and Harnischfeger needed other sources of income, so in 1893 they began to design “earth-moving machines.” Pawling became ill and sold his part of the business to Harn­­ischfeger in 1911.

Limestone mined from Coquina Mine was used for poultry grit, cattle feed and other agricultural purposes.
Embedded in limestone are thousands of shell fossils. This was mined for Calcium Carbonate.

In 1920, the P&H Model 206 – a small power shovel – cemented the company’s place in the construction and mining industries. In the decades that followed, the company moved on to larger and larger machines; what began as a small dipper capable of lifting 500 pounds would eventually become massive power shovels capable of extracting 120 tons of material from the earth. But for all of its successes, the P&H Company would ultimately meet its downfall, all due to asbestos in its brake linings. 

Coquina Mine’s P&H Model 206 power shovel is still is good condition after nearly 100 years.
Here's the boom, stick and hoist cables on the power shovel. This relic is nearly 100 years old.

Asbestos was touted as a “miracle mineral” for much of the 20th century, largely because its fire-retardant properties. At P&H’s manufacturing plants, brake linings regularly had to be grinded down in order to fit casings on cranes and other machinery. The process released large amounts of asbestos dust into the air, polluting the work environment and putting workers’ health at risk. With a large number of asbestos-related lawsuits pending against it, Harnischfeger filed for Chapter 11 bankruptcy protection in 2000. Today, P&H Mining Equipment is a subsidiary of Joy Global Inc., a global leader in mining solutions. Its headquarters remain in Milwaukee, with additional offices around the world. 

Located far below Coquina Mine, this may have been part of a conveyor or elevator system.
The first artifact on the way to the mine. It looks like part of a conveyor or elevator system.


Las Llajas Canyon

Las Llajas (pronounced YAH huhs) Canyon lies directly to the east of Coquina Mine. Most of it was a 1920s residential subdivision called Marrland, owned by Howard Marr. The name Las Llajas was first used in 1931, and is likely a misspelling of the Spanish words “Las Llagas” which translates to “the wounds”, referring to the stigmata of a Roman Catholic saint. From 1914-1920 a cult called Pisgah Grande lived in this canyon, and created a secluded colony with thirty buildings. It had over 300 members. If you look in the right places you can still find old bricks stamped with Pisgah markings where the buildings used to rest. These people were peaceful, but more sinister cults were drawn to this general area as well, such as the Blackburn Cult, Califa's Children and the infamous Manson Family.

Once owned by Howard Marr, this land is now mostly known as Marrland Open Space.
Las Llajas Canyon looking toward Simi Valley. This land was once owned by Howard Marr.

A Brief History of Simi Valley

Simi Valley's name is derived from the Chumash word Shimiyi, which refers to the stringy, thread-like clouds that typify the region. The accent is meant to be on the second I, pronounced Sim-ee, although virtually no one pronounces it correctly. Three Chumash settlements existed in Simi Valley during the Mission period in the late 18th and early 19th century: Shimiyi, Ta’apu and Kimishax or Quimisac. Hidden on the hillsides of Simi Valley are many Chumash cave paintings containing pictographs, the most famous of which were found in the Burro Flats Painted Cave. But good luck getting to that one. It’s located on private property owned by Boeing, a virtual Area 51 that experienced one of the worst nuclear disasters in America back in the late 1950s. Most of the other cave paintings are located near Lake Manor and Chatsworth.

Painted Cave was a winter solstice observatory for the Chumash, now located on private land.
Burro Flats Painted Cave was a winter solstice observatory for the Chumash.

The first Europeans to visit Simi Valley were members of the Spanish Portola Expedition (1769–1770), the first European land entry and exploration of the present-day state of California. The expedition traversed this valley on January 13–14, 1770, traveling from Conejo Valley to San Fernando Valley. They camped near a native village on the 14th. Rancho Simi, also known as Rancho San José de Nuestra Senora de Altagracia y Simi, was a 113,009-acre Spanish land grant given to Francisco Javier Pico and his two brothers in 1795. This was the earliest Spanish colonial land grant within Ventura and Santa Barbara Counties. Rancho Simi was bought from the Pico family in 1842 by Jose de la Guerra y Noriega, who used it to raise his cattle.

An unusual structure found on the way to the mine. This may have been part of a ranch house.
Currently a bee farm, this old structure may have been part of a ranch house at one time.

In 1858 the land was again sold to the Philadelphia and California Petroleum Company, however not much oil was discovered here. In 1887 some of the land was bought by a newly formed company, the Simi Land and Water Company. The small colonial town known as "Santa Susana del Rancho Simi" throve in the late 19th century and had a Spanish-speaking majority. For a short time Simi Valley was known as Simiopolis, but was shortened to Simi by 1910. The city of Simi Valley was not incorporated until 1969, when the area had only 10,000 residents, ten year after one of the worst nuclear disasters in U.S. history, at the Santa Susana Field Laboratory. The full extent of this disaster was covered up by the government for nearly 50 years, but was said to have released up to 400 times more radiation into the environment than Three Mile Island.

There are an abundance of wildflowers near Coquina Mine in spring. These called Blue Dicks.
Blue Dicks found near Coquina Mine. In the spring these hills are teaming with wildflowers.

Side Trip To Cave of Munits 

When in limestone country, look for limestone caves. Simi Valley is located at the easternmost edge of Ventura County. The Cave of Munitz can be found on the westernmost edge of Los Angeles County, in an area called Las Virgines Canyon Open Space. The Cave of Munits is actually a large cleft, eroded into a limestone wall, near Castle Peak in West Hills. It is believed to be the cave of a mythical Chumash shaman who was killed after murdering the son of a Chumash chief. This cave has appeared in the films The Canyon of Missing Men (1930) and Tarzan and the Golden Lion (1927).

This is the mouth of the Cave of Munits. This immense hole is sometimes used by rockclimbers.
The mouth of the Cave of Munits has a huge limestone opening, often used by rock climbers. 

Castle Peak, also known as Escorpión Peak is the corrupted American form of the Ventureño Chumash name for the peak, which was kas'ele'ew. This area was inhabited for about 8,000 years by Native Americans of the Tongva-Fernandeño and Chumash-Ventureño tribes that lived in the Simi Hills and close to tributaries of the Los Angeles River. A village called Hu'wam was located at the base of Castle Peak near the mouth of Bell Canyon and was a meeting and trading point for these two tribes. Tataviam tribes also lived in this area. 

Looking up inside the Cave of Munits. There are numerous hole above, illuminating the inside.
Believed to be the cave of a mythical Chumash shaman, killed after murdering the son of a chief.

In 1769 Juan Bautista de Anza led the first European exploration by land of Las Californias. It passed through this area, known at the time as Ranch El Escorpión which was a 1845 Mexican land grant named after the Peak. From the 1920s to the 1950s many Westerns and other types of motion pictures were filmed here at the Laskey Mesa movie ranch area. Today Upper Las Virgenes Canyon Open Space Preserve is a large nature preserve owned and operated by the Santa Monica Mountain Conservancy spanning nearly 3,000 acres in the Simi Hills of western Los Angeles County and eastern Ventura County. It was previously called Ahmanson Ranch Park.

In Chumash mythology a shaman was killed in this cave, after murdering the son of a chief.
To give you some perspective, the bright area seen in the lower center is about 15 feet high.