Strathearn, served as the headquarters of the rancho.
A few years after Jose de la Guerra's death in 1858, the rancho was sold to the Philadelphia and California Petroleum Company headed by Pennsylvania Railroad president, Thomas A. When no great amount of oil was discovered, Scott began to sell the rancho.In 1887, a portion of the rancho was bought by a newly formed company, the Simi Land and Water Company.For a brief time, its postal address was known as Simiopolis, though it was soon shortened again to Simi by 1910.The first public school was built in 1890 in the northeast but was torn down in 1926.The city sits next to Thousand Oaks, Moorpark, and Los Angeles.
The city's 2014 population has been estimated at 126,871, up from 111,351 in 2000.
Roughly 2,000 years later, as hunting and fishing techniques improved, the population increased significantly.
The native people who inhabited Simi Valley spoke an interior dialect of the Chumash language, called Ventureño.
The small colonial town known as "Santa Susana del Rancho Simi" throve in the late 19th century and had a Spanish-speaking majority, but since then many Anglo-Americans have arrived to settle.
Farms, orchards and groves dominated the valley's landscape until the 1970s.
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, and West Hills and Bell Canyon.