History of Imperial County, California in Timeline

By Popular Timelines Editorial Team · Updated: December 20, 2024

Imperial County, established in 1907, is the least populated county in Southern California. Located on California's southeast border, it was created from eastern San Diego County. With a population just shy of 180,000 as of 2020, its county seat and largest city is El Centro.

1900: Early Settlement

Around 1900, permanent settlements began to increase in Imperial County, although small-scale settlements in natural aquifer areas had existed since the early 19th century.

1905: Colorado River Flood and Formation of the Salton Sea

In 1905, heavy rainfall caused the Colorado River to flood, leading to the formation of the Salton Sea as waters collected in the Salton Sink.

1907: Naming of Imperial County

Imperial County, named after Imperial Valley, was formed in 1907. Imperial Valley got its name from the Imperial Land Company.

1910: Development and Disruption

By 1910, the Imperial Land Company had established numerous farms, but the Mexican Revolution significantly disrupted their plans, impacting the lives of many farmers and their families.

1910: Population Baseline

In 1910, Imperial County had a significantly smaller population compared to later years, serving as a baseline for measuring subsequent growth.

1948: Start of All-American Canal Construction

Construction of the All-American Canal from the Colorado River to Imperial Valley began in 1948.

1950: Population Growth

By 1950, Imperial County's population exceeded 50,000, a substantial increase from its 1910 population.

1951: Completion of All-American Canal

The All-American Canal, supplying water to Imperial Valley, was completed in 1951.

1994: Establishment of North Algodones Dunes Wilderness

The North Algodones Dunes Wilderness was established in 1994 under the California Desert Protection Act, restricting motorized access.

March 22, 1997: Area Code 760 Split

On March 22, 1997, area code 760 was created by splitting from area code 619, covering a large area including the El Centro metropolitan area, Palm Springs, Oceanside, and parts of southeastern California.

2000: 2000 Census Data

The 2000 census provided data on Imperial County's population, households, families, population density, housing units, racial makeup, and language spoken at home.

2000: Population Baseline

The year 2000 serves as a reference point for measuring population growth in Imperial County, with a recorded population used for comparison with later figures.

2005: Filming of "Jarhead"

Parts of the 2005 film "Jarhead" were filmed in Imperial County due to the area's resemblance to the desert terrain of Iraq.

2006: Population Growth

By 2006, Imperial County's population reached 160,201, marking a 30% increase since 2000, attributed to immigration, affordable housing, and retirement migration.

April 2008: Renewable Energy Boom in Imperial Valley

In April 2008, the Bureau of Land Management (BLM) had received 163 applications for renewable energy projects on 1,600,000 acres in California, mostly in Imperial Valley. This surge in applications was driven by California's renewable energy mandate, abundant sun resources, high unemployment, proximity to population centers, and available desert land.

November 4, 2008: Proposition 8 Vote

On November 4, 2008, Imperial County showed significant support for Proposition 8, which banned same-sex marriage in California.

2008: High Unemployment During Great Recession

During the Great Recession of 2008-2011, El Centro, located in Imperial County, experienced an exceptionally high unemployment rate, exceeding 30-34%.

2009: Area Code 442 Overlay

In 2009, area code 442 was introduced as an overlay to area code 760.

2010: California's Renewable Energy Mandate

By 2010, California aimed to generate 20% of its power from renewable sources, contributing to the rise of renewable energy projects in Imperial Valley.

2010: 2010 Census Demographics

The 2010 United States Census recorded Imperial County's population at 174,528, providing a detailed breakdown of the racial and ethnic makeup of the county.

2010: 2010 Census of Imperial County

The 2010 census provided data on the population of Imperial County, used for ranking the population.

February 6, 2012: Legal Standing Denied in Hollingsworth v. Perry

On February 6, 2012, the Ninth Circuit Court of Appeals denied Imperial County's legal standing in the Hollingsworth v. Perry case related to Proposition 8.

2015: Stirling Energy's Solar Thermal Plant

Around 2015, Stirling Energy's massive solar thermal plant in Imperial Valley, spanning 10 square miles with 38,000 "sun catchers," was expected to be fully operational, with the capacity to power up to 600,000 homes.