Simi Valley (; Chumash: Shimiyi) is a city in the valley of the same name in southeastern Ventura County, California, United States. It is 37 miles (northwest of Downtown Los Angeles, making it part of the Greater Los Angeles Area. Simi Valley borders Thousand Oaks, Moorpark, and the Chatsworth neighborhood of Los Angeles. As of the 2020 U.S. census the population was 126,356, up from 124,243 in 2010. The city of Simi Valley is surrounded by the Santa Susana Mountains and the Simi Hills, west of the San Fernando Valley, and northeast of the Conejo Valley. It grew as a bedroom community for the cities in the Los Angeles area and the San Fernando Valley when a freeway was built over the Santa Susana Pass.
The Ronald Reagan Presidential Library, where the former president was buried in 2004, is in 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 name could have originated from the strands of mist from coastal fog that move into the Oxnard Plain and wind their way up the Calleguas Creek and the Arroyo Las Posas into Simi Valley. The origin of the name was preserved because of the work of the anthropologist John P. Harrington, whose brother, Robert E. Harrington lived in Simi Valley. Robert Harrington later explained the name: "The word Simiji in Indian meant the little white wind clouds so often seen when the wind blows up here and Indians living on the coast, would never venture up here when those wind clouds were in the sky. The word Simiji was constructed by whites to the word Simi. There are other explanations about the name Simi, but this one was given to me by my brother who worked over 40 years for the Smithsonian Institution and it seems most plausible to me".
Three Chumash settlements existed in Simi Valley during the Mission period in the late 18th and early 19th century: Shimiyi, Ta'apu (Tapo Canyon), and Kimishax or Quimicas (Camp Canyon west of Moorpark College). There are many Chumash cave paintings in the area containing pictographs, including the Burro Flats Painted Cave in the Burro Flats area of the Simi Hills, located between the Simi Valley, West Hills, and Bell Canyon. The cave is located on private land owned by NASA. Other areas containing Chumash Native American pictographs in the Simi Hills are by Lake Manor and Chatsworth.
The first Europeans to visit Simi Valley were members of the Spanish Portol expedition (the first European land entry and exploration of the present-day state of California. The expedition traversed the valley on January 1314, 1770, traveling from Conejo Valley to San Fernando Valley. They camped near a native village in the valley on the 14th.
Rancho Sim, also known as Rancho San Jos de Nuestra Seora de Altagracia y Sim, was a 113,009-acre (Spanish land grant in eastern Ventura and western Los Angeles counties granted in 1795 to Santiago Pico. After Santiago Pico's death in 1815, the Rancho was regranted to Santiago's sons Javier Pico and his two brothers, Patricio Pico and Miguel Pico, members of the prominent Pico family of California. Rancho Sim was the earliest Spanish colonial land grant within Ventura and Santa Barbara Counties. The name derives from Shimiji, the name of the Chumash Native American village here before the Spanish. It was the largest Spanish or Mexican land grant given in Ventura County, and one of the largest given in California. The Simi Adobe-Strathearn House, later the home of Robert P. Strathearn and family, served as the headquarters of the rancho.
Jos de la Guerra y Noriega, a Captain of the Santa Barbara Presidio, who had begun to acquire large amounts of land in California to raise cattle, purchased Rancho Sim from the Pico family in 1842. After Jose de la Guerra death in 1858, the sons of Jose de la Guerra continued to operate the ranchos. The end of their prosperity came when several years of drought in the 1860s caused heavy losses. In 1865, the De la Guerras lost the ownership of El Rancho Sim excluding the Rancho Tapo. El Rancho Tapo was part of the original 113,009-acre Rancho Sim grant, but sometime around 18201830, the Rancho Tapo came to be thought of as a separate place within Rancho Sim. The last of the De la Guerras to live in Sim Valley retreated to a 14,400-acre portion of the original rancho that was known as the Tapo Rancho. As late as February 1877, Juan De la Guerra was reported in county newspapers to be preparing to plant walnuts in the Tapo, which appears to be the final mention of their farming in relation to the original Sim grant.
The De la Guerra heirs tried every legal means, but by the 1880s, the Rancho Tapo also slipped from their ownership, as had the rest of the Rancho.
The Pioneer, or 'American,' period in Simi Valley began with the 96,000-acre purchase of El Rancho Sim by an eastern speculator named Thomas A. Scott (who had made his money as an investor in the Pennsylvania Railroad during the Civil War. He was president of the Pennsylvania Railroad, and a partner in Philadelphia and California Petroleum Company. Scouts came to California to purchase lands, and thus Scott acquired El Rancho Sim (His goal was to locate sites for oil, since the first oil well had been developed in Titusville, Pennsylvania just a few years earlier (Within a short time, a 27-year-old man named Thomas Bard was sent west by Scott to manage the California properties. In the late 1880s, Sim Land and Water Company was formed to see to the selling of the huge rancho in ranch-size properties. Some American farmers had begun to lease land in the greater Rancho Sim for farming.
The earliest Anglo American ranchers showed up in Sim Valley in the late 1860s into the 1870s. Charles Emerson Hoar was given the title of "first American farmer" by early Sim historian Janet Scott Cameron. He had purchased the Hummingbird's Nest Ranch in the northeast corner of the Valley, and he leased land from the new owners of the Sim Rancho for raising sheep, already a proven way of making a living.
Much of the Sim Rancho land continued, as in Spanish days, to be used for raising sheep, cattle and grain. Wheat was more likely to prosper here than in the rest of the county, being free of wheat leaf rust, a fungal disease. Barley soon became the predominant grain crop.
Agriculture and ranching dominated the landscape through the 1950s. Citrus, walnuts and apricots were all grown in Simi Valley. In the early 1960s modern residential development began to take place.
When Sim was an agricultural community, there were ranch houses that dotted the Valley. Four distinct communities also were located in the Valley ('Four Communities of Simi Valley' section below) prior to modern residential development. Though 1957 and 1958 brought the first 'tract' housing developments when the Dennis and Ayhens, Wright Ranch and Valley Vista tracts were built, the tremendous 'boom' in residential development took place beginning in 1960. The population which was 4,073 in 1950 doubled to 8,110 in 1960. By 1970 the population in Simi is reported by the census as 59,832.
The pioneers arrived in the late 1860s 1870s and ever since, this has been 'The Valley of Simi.' But, not all the communities in the valley were known as 'Simi.' There was the township of Simi (as 'Simiopolis' for about a six-month period in 1888). In the valley there were also the communities of Santa Susana, Community Center and the Susana Knolls (first as Mortimer Park) at different points in time.
Simi In late 18871888, the incorporation of Simi Land and Water Company came about. El Rancho Sim was divided into ranches and farms by that corporation, and advertised for sale to midwestern and New England states. An investor group, the California Mutual Benefit Colony of Chicago, purchased land and laid out a townsite (between First and Fifth Streets and from Los Angeles south to Ventura Ave), named it 'Simiopolis' and shipped twelve pre-cut, partially assembled houses from a lumberyard in Chicago via rail to Saticoy, then brought by wagon to Simi. These are known as 'colony houses.' This was the first 'neighborhood' in Simi. Stores sprung up on Los Angeles Ave, and the first Simi School was built in 1890 on Third and California Streets, and was used until Simi Elementary was built in the mid-1920s.
Santa Susana In 1903 the Santa Susana Train Depot was built, and the railroad was complete through Simi Valley, except for the tunnel, which was completed in 1904. A small business community grew up near the Santa Susana Train Depot, which was located on the north side of Los Angeles Ave, just east of Tapo Street. Over time residential developments followed and the town of Santa Susana was born. The Depot was moved in 1975 by Rancho Simi Recreation and Park District to its current location off of Kuehner.
Community Center In 1922 L.F. Roussey laid out the small development which became known as Community Center. The driving force behind this development was the need for a High School in Simi Valley, as well as an elementary school in a more central location in the valley. The first graduating class from Simi High School was 1924, Simi Elementary was completed in 1926, The Methodist Church (is now the Cultural Arts Center) was built in 1924. Numerous houses were built in Community Center in the 1920s and 1930s. The Simi Valley Woman's Club was located there as well (building which served as the clubhouse for the Woman's Club was moved from the town of Simi). The Woman's Club club house was used by many individuals and organizations as a community meeting place.
Mortimer Park (Susana knolls) The area that is now the Knolls was a nearly 1,800-acre parcel of land (that was purchased by Mr. and Mrs. Lewis T. Mortimer in the early 1920s. They planned on selling the lots for cabins, or vacation homes. The lots were very small (x 50 feet), and the Mortimers did not take the mountainous nature of the land into account, so quite often the lots were not buildable. Oftentimes several lots were needed to build structures. In 1944 the Garden Club, an active community organization in the area petitioned the county supervisors to change the name of Mortimer Park to the Susana Knolls.
The first attempt to incorporate the towns of Simi, the area known as Community Center (and Santa Susana (in 1966 was unsuccessful. The second attempt in 1969 was successful, with residents voting 6,454 to 3,685 in favor of incorporation. 59% of eligible voters turned out for this vote. Susana Knolls is an unincorporated area of the Valley. Voters also voted whether to call this newly incorporated city 'Santa Susana' or 'Simi Valley.' The name Simi Valley garnered 2,000 more votes than Santa Susana.
The 2,848 acres (Santa Susana Field Laboratory located in the Simi Hills, was used for the development of pioneering nuclear reactors and rocket engines beginning in 1948. The site was operated by Atomics International and Rocketdyne (both divisions of the North American Aviation company). The Rocketdyne division developed a variety of liquid rocket engines. Rocket engine tests were frequently heard in Simi Valley. The Atomics International division of North American Aviation designed, built and operated the Sodium Reactor Experiment, which in 1957 became the first United States commercial nuclear reactor to supply electricity to a public power system, when it powered the city of Moorpark (government owned BORAX-III reactor had previously powered Arco, Idaho for around an hour in 1955). The last nuclear reactor operated at SSFL in 1980 and the last rocket engine was produced in 2006. The SSFL has been closed to development and testing. The site is undergoing investigation and removal of the nuclear facilities and cleanup of the soil and groundwater. The Boeing Company, the US DOE, and NASA are responsible for the cleanup.
In July 1959, the Sodium Reactor Experiment suffered a serious incident when 13 of the reactor's 43 fuel elements partially melted resulting in the controlled release of radioactive gas to the atmosphere. The reactor was repaired and returned to operation in September 1960. The incident at the Sodium Reactor Experiment has been a source of controversy in the community. Technical analysis of the incident intended to support a lawsuit against the current landowner (Boeing Company) asserts the incident caused the much greater release of radioactivity than the accident at Three Mile Island. Boeing's technical response concludes the monitoring conducted at the time of the incident, shows only the allowable amount of radioactive gasses were released, and a Three Mile Island-scale release was not possible. The case was settled, it is reported, with a large payment by Boeing. In September 2009, The U.S. Department of Energy sponsored a public workshop where three nuclear reactor experts shared their independent analysis of the July 1959 incident.
The Santa Susana Field Laboratory also hosted the Energy Technology Engineering Center. The center performed the design, development and testing of liquid metal reactor components for the United States Department of Energy from 1965 until 1998.
The Santa Susana Field Laboratory includes sites identified as historic by the American Institute of Aeronautics and Astronautics and by the American Nuclear Society. The National Register of Historic Places listed Burro Flats Painted Cave is located within the Santa Susana Field Laboratory, on a portion of the site owned by the U.S. Government. The drawings within the cave have been termed "the best preserved Indian pictograph in Southern California"[citation needed].
Simi Valley is a city located in the very southeast corner of Ventura County, bordering the San Fernando Valley in Los Angeles County, and is a part of the Greater Los Angeles Area. The city of Simi Valley primarily consists of the eponymous valley itself. The city of Simi Valley borders the Santa Susana Mountains to the north, the Simi Hills to the east and south, and is adjacent to Thousand Oaks to the southwest and Moorpark to the west. Simi Valley is connected to the nearby San Fernando Valley by the Santa Susana Pass in the extreme east of Simi Valley. The syncline Simi Valley is located in the western part of the region called the Transverse Ranges. While the Santa Susana Mountains separate the valley from the Los Padres National Forest in the north, the Simi Hills separate it from Conejo Valley in the south. In the extreme east is Rocky Peak, one of Santa Susana Mountains' highest peaks, which is a dividing line between Ventura County to the west and Los Angeles County to the east. On the other side of the valley, in the extreme west side of Simi Valley is Mount McCoy, which may be most known for its 12ft. concrete cross that sits at its peak. The physiographical valley is a structural as well as a topographic depression. The Simi Valley, just as neighboring San Fernando Valley, owes its existence and shape to the faulting and folding of the rocks. It is essentially a structural valley and not wholly the work of erosion. It is drained by the Calleguas Creek and also its principal tributary, Conejo Creek. Both of these originate in the Santa Susana Mountains.
According to the United States Census Bureau, the city has a total area of 42.2 sq mi (comprising 41.5 sq mi (of land and 0.77 sq mi (or 1.81%, of it is water. Simi Valley is located northwest of the Los Angeles neighborhood of Chatsworth and approximately 30mi (from Downtown Los Angeles, 380mi (south of San Francisco, 160mi (north of San Diego, and 350mi (south of Sacramento. Commutes to Los Angeles are usually via the State Route118 (Reagan Freeway) or the Southern California Metrolink commuter train, which makes several daily trips from Simi Valley. Simi Valley has a mediterranean climate. Temperate variations between day and night tend to be relatively big. The mean annual temperature is 64.1 degrees (while the annual precipitation is 18.39 inches (The precipitation remains less than one inch for seven months April until October, while the precipitation exceeds four inches in the two wettest months January and February. While the mean temperature is at its lowest at 53.6 degrees (in December, the mean temperature in July and August exceeds 76 degrees (Valley has been the victim of several natural disasters, including the flood of 1967, the storm of 1983, the 1988 lightning strike, as well as the 1994 Northridge earthquake and numerous wildfires.
Simi Valley has a warm and dry climate during summer when mean temperatures tend to be in the 70s. Wildfires do also occur here. The city's climate cools during winter when mean temperatures tend to be in the 50s. Because of its relatively low elevation, the Simi Hills typically experience rainy, mild winters. Snow is rare in the Simi Hills, even in the highest areas. The warmest month of the year is August with an average maximum temperature of 96F (while the coldest month of the year is December with an average minimum temperature of 38F (Temperature variations between night and day tend to be relatively large during summer, with a difference that can reach 38F (and moderate during winter with an average difference of 29F (The annual average precipitation in Simi Valley is 17.9 inches. Winter months tend to be wetter than summer months. The wettest month of the year is February with an average rainfall of 4.8 inches. Simi Valley gets 18 inches of rain per year, while the United States average is 37. Snowfall is 0 inches, while the U.S. average is 25 inches of snow per year. The number of days with measurable precipitation is 25. On average, there are 277 sunny days in Simi Valley per year. The July high is approximately 96F (The January low is 39F (The record low is 18 degrees Fahrenheit ((in February 1989) and the record high is 116 degrees Fahrenheit ((in August 1985).
An aspect of Simi Valley's location, situated beside the Simi Hills, is that it lies in a high-risk area for the wildfires that sweep through Southern California's mountain ranges every few years. Simi Valley is also at risk for earthquakes. The valley is surrounded by faults; the closest ones being the Santa Rosa Fault to the Northwest, the Northridge Hills Fault to the Northeast, and the Chatsworth Fault to the South. In 1994, portions of Simi Valley received significant damage from the Northridge earthquake.
In autumn 2003, the Simi Fire burned about 108,000 acres. A 2005 fire started on September 28 and burned an estimated 7,000 acres (On September 29, the fire was estimated to be 17,000 acres (More than 1,000 firefighters worked against the tricky combination of dry brush, low humidity and temperatures in the high 90s along the line that divides Los Angeles and Ventura counties. The fire was later brought under control and extinguished, without serious injury. Three homes were lost in outlying areas, but none within the city limits.
Neighborhoods include:
The Simi Hills are a wildlife corridor linkage from the Santa Monica Mountains to the Topatopa Mountains, San Gabriel Mountains, and other Transverse Ranges further east. Simi Hills' undeveloped native habitat provides routes that protect larger land wildlife of the Santa Monica Mountains from genetic isolation. Large sections of the Simi Hills are protected by parks and open space preserves.[citation needed]
Before the 1960s, Simi Valley once boasted a strong community of Latino families, many of whom worked for white ranchers. However, the housing boom in the 1960s and 1970s attracted many white Americans leaving urban areas in Los Angeles and the San Fernando Valley. This turned Simi Valley into a predominately white city, but the percentage of those who identified as non-Hispanic white began to decrease from 86.2% in 1980 to 54% in 2020.
The 2010 United States census reported that Simi Valley had a population of 124,237. The population density was 2,940.8 inhabitants per square mile ( The racial makeup of Simi Valley was 93,597 (White, 1,739 (African American, 761 (Native American, 11,555 (Asian, 178 (Pacific Islander, 10,685 (from other races, and 5,722 (from two or more races. Hispanic or Latino of any race were 10,938 persons (16.2% of Simi Valley's population were Mexican-American, 1.2% Salvadoran, 0.9% Guatemalan, 0.6% Puerto Rican, 0.6% Peruvian, 0.3% Cuban, 0.3% Argentine, 0.2% Honduran, 0.2% Nicaraguan, and 0.2% Ecuadorian. Among Asian-Americans, 2.7% of Simi Valley's population were Indian-Americans, 2.2% Filipino, 1.2% Chinese, 1.0% Vietnamese, 0.7% Korean, 0.5% Japanese, 0.2% Thai, 0.1% Pakistani. The majority of Simi Valley's population was made up of Caucasian-Americans; the largest groups of whites were 16.7% German-American, 11.3% English, 8.5% Italian, 3.4% French, 3.1% Polish, 2.3% Norwegian, 2.3% Swedish, 2.1% Scottish and 2% Dutch.
The Census reported that 123,577 people (of the population) lived in households, 482 (lived in non-institutionalized group quarters, and 178 (were institutionalized. There were 41,237 households, out of which 16,765 (had children under the age of 18 living in them, 24,824 (were opposite-sex married couples living together, 4,659 (had a female householder with no husband present, 2,214 (had a male householder with no wife present. There were 1,975 (unmarried opposite-sex partnerships, and 291 (same-sex married couples or partnerships. A total of 7,087 households (were made up of individuals, and 3,013 (had someone living alone who was 65 years of age or older. The average household size was 3.00. There were 31,697 families (of all households); the average family size was 3.33.
The population was spread out, with 31,036 people (under the age of 18, 11,088 people (aged 18 to 24, 33,890 people (aged 25 to 44, 35,046 people (aged 45 to 64, and 13,177 people (who were 65 years of age or older. The median age was 37.8 years. For every 100 females, there were 96.6 males. For every 100 females age 18 and over, there were 94.4 males. There were 42,506 housing units at an average density of 1,006.1 per square mile (of which 30,560 (were owner-occupied, and 10,677 (were occupied by renters. The homeowner vacancy rate was 1.2%; the rental vacancy rate was 4.6%. 93,181 people (of the population) lived in owner-occupied housing units and 30,396 people (lived in rental housing units.
As of the 2000 United States census, there were 111,351 people, 36,421 households, and 28,954 families residing in the city. The population density was 1,097.3/km (There were 37,272 housing units at an average density of 367.3/km (The racial makeup of the city was 81.33% White, 1.26% Black or African American, 0.70% Native American, 6.33% Asian, 0.14% Pacific Islander, 6.50% from other races, and 3.74% from two or more races. 16.82% of the population were Hispanic or Latino of any race.
There were 36,421 households, out of which 42.5% had children under the age of 18 living with them, 63.9% were married couples living together, 10.7% had a female householder with no husband present, and 20.5% were non-families. 14.7% of all households were made up of individuals, and 4.9% had someone living alone who was 65 years of age or older. The average household size was 3.04 and the average family size was 3.33.
In the city, the population was spread out, with 28.4% under the age of 18, 7.9% from 18 to 24, 32.9% from 25 to 44, 23.1% from 45 to 64, and 7.6% who were 65 years of age or older. The median age was 35 years. For every 100 females, there were 97.9 males. For every 100 females age 18 and over, there were 95.6 males.
According to a 2022 estimate, the median income for a household in the city was $112,144. 7.02% of the population and 7.4% of families were below the poverty line. In 2022, the median income for a household in Simi Valley has increased to $112,114 according to the U.S. Census Bureau. The median per capita income for the past 12 months (was $51,324. Sales tax was at 7.25% and income taxes were at 8.00%. The current unemployment rate was at 4.10% with a 0..46% recent job growth compared to the National Unemployment Rate of 5.20% and a 1.59% job growth. The median cost of homes in Simi Valley was $704,200 with mortgages at a median of $3,047.
Commuting to Los Angeles for work is done by 27% of Simi Valley residents, with 20% working within Simi Valley.
The primary industry is machinery and tools with 69 firms, and the secondary is the metal industry with 51 firms. Other industries include lumber/wood products, food, plastic products, apparel/textiles and minerals.
The largest division of Countrywide Financial has been headquartered in the city since the mid-1990s.[citation needed]
According to the city's 2022-2023 Comprehensive Annual Financial Report, the top employers in the city are:
The Ronald Reagan Presidential Library, located in Simi Valley, was visited by almost 400,000 people in 2014. After the death and state funeral of Ronald Reagan, the former US president was buried at the library in June 2004. The library adjoins a hangar in which the Boeing 707 SAM 27000 (Force One), which served presidents Nixon through G.W. Bush, is housed and available for tours. In the pavilion are various automobiles used to transport the president, as well as Marine One, the presidential helicopter.
The Simi Valley Public Library opened in July 2013, and served 200,000 patrons that year.
Simi Valley has 5,600 acres (of public owned land, including hundreds of acres of land in the Simi Hills.
Iceoplex is an ice skating facility and home location of the Cal State Northridge Matadors hockey program.
Notable publicly-owned parks and recreational fascilites in Simi Valley include:
Simi Valley's government uses the "council-manager" form of government. This means that the city council is composed of one mayor, elected every two years, and four council members elected for four-year terms. The city council appoints both the city attorney and city manager, who heads the executive branch of the city government. The city manager appoints the various department heads for the city, and acts as the city clerk and city treasurer.
According to the 20082009 Comprehensive Annual Financial Report Fund Financial Statements, the city's various funds had $89.3 million in Revenues, $86.3 million in expenditures, $139.9 million in total assets, $26.1 million in total liabilities, and $158.5 million in investments.
Simi Valley was at one time considered a conservative stronghold politically, along with the neighboring city of Thousand Oaks. However, in recent elections, both cities have become left-leaning.
In the state legislature, Simi Valley is in the 27th senatorial district, represented by Democrat Henry Stern, and in the 42nd Assembly district, represented by Democrat Jacqui Irwin.
In the United States House of Representatives, Simi Valley is in California's 26th congressional district, represented by Democrat Julia Brownley. In the United States Senate, California is represented by Alex Padilla[100] and Adam Schiff.[101]
As of the 2024 General Election results, all of Simi Valley's elected representatives are from the Democratic Party.[102][103][104]
In November 2018, Katie Hill unseated Republican Steve Knight and became the first Democratic woman to represent the district in the House of Representatives. Additionally, in 2022, Alex Padilla became the first Latino elected to the Senate from California.[105]
Simi Valley is served by the Simi Valley Unified School District.
There are five high schools located in Simi Valley: Royal High School, Grace Brethren High School, Santa Susana High School, Simi Valley High School, and Apollo High School (continuation school).
There are three middle schools located in Simi Valley: Hillside Middle School, Valley View Middle School, and Sinaloa Middle School.
Schools of higher education in Simi Valley include Eternity Bible College and American Jewish University.
The Montalvo Cutoff, a railroad line opened by the Southern Pacific Railroad on March 20, 1904, to improve the alignment of its Coast Line, runs eastwest through the valley.[106] In 1905, the longest train tunnel in the United States at that time was completed at the east end of Simi Valley. Tunnel #26 is still being used linking Simi Valley and the San Fernando Valley through the Santa Susana Mountains.[107][108][109] The area was originally served by the Santa Susana Depot which was also opened in 1904 as a combination passenger and freight depot built by the Southern Pacific and located on Los Angeles Avenue near Tapo Street. The station remained in use for the 60 years.[citation needed]
Simi Valley station is used by Amtrak and Metrolink on the railroad's Ventura County Line, and by Simi Valley Transit.
Law enforcement is provided by the Simi Valley Police Department, and the Ventura County Fire Department provides fire protection. American Medical Response, in conjunction with Ventura County Fire Department, provide emergency medical services at the Advanced Life Support level.[citation needed]