Fresno County is a county located in the Central Valley of the U.S. state of California, south of Stockton and north of Bakersfield. As of 2008, it is the tenth most populous county in California with an estimated population of 931,098, and the sixth largest in size with an area of 6,017.4 square miles. The county seat is the city of Fresno.
The area now known as Fresno County, once a semiarid steppe, was discovered by Spaniards during a search for suitable mission sites. In 1846, this area became the property of the United States as a result of the Mexican War.
Fresno County was formed in 1856 from parts of Mariposa, Merced and Tulare counties. Parts of Fresno County's territory were given to Mono County in 1861 and to Madera County in 1893. The original county seat was placed in Millerton.
The county is named after Fresno Creek. Fresno in Spanish signifies "ash tree" and it was due to the abundance of mountain ash or ash trees in the county that it received its name.
The settling of Fresno County was not without its conflicts, land disputes, and natural disasters. Floods caused immeasurable damage to the Millerton area so much so that the county seat was moved to Fresno and the little town never fully recovered. Fires also plagued the settlers of Fresno County. In 1882, the greatest of the early day fires wiped out an entire block of the city of Fresno, and was followed by another devastating blaze in 1883.
At the same time residents brought irrigation, electricity, and extensive agriculture to the area. Moses Church developed the first canals, called "Church Ditches," for irrigation. These canals transformed the barren desert of Fresno County into rich soil, thus enabling extensive wheat farming in Fresno County. Frances Eisen, leader of the wine industry in Fresno County, also began the raisin industry in 1875, when he accidentally let some of his grapes dry on the vine. A.Y. Easterby and Clovis Cole (aka the "Wheat King of the Nation") developed extensive grain and cattle ranches. These and other citizens laid the groundwork for the cultivation of Fresno County - now the nation's leading agricultural region.
The discovery of oil in the western part of the county, near the town of Coalinga at the foot of the Coast Ranges, brought about an economic boom in the first decade of the 20th century, even though the field itself was known at least as early as the 1860s. By 1910, Coalinga Oil Field, the largest field in Fresno County, was the most richly productive oil field in California; a dramatic oil gusher in 1909, the biggest in California up until that time, was an event of sufficient excitement to cause the Los Angeles Stock Exchange to close for a day so that its members could come by train to view it. The Coalinga field continues to produce oil, and is currently the eighth-largest field in the state.
To date, over thirty structures in Fresno County are on the National Register of Historic Places, including the Fresno Water Tower, which once held over 250,000 US gallons of water for the city of Fresno, the Meux Home, and Kearney Mansion Museum.