The present-day site of El Dorado County was once home to the Maidu, Washoe, and Miwok Native American tribes, and is notable for being the site of the 1848 gold discovery that sparked the California Gold Rush. The County of El Dorado was one of California's original 27 counties created effective February 18, 1850 (the number has risen to 58 today). Its name is derived from the Spanish meaning "the gilded/golden".
The final segments of the Pony Express mail route ran through El Dorado County until its replacement with the telegraph service in 1861; U.S. Highway 50 follows the Pony Express route today.
The El Dorado County Sheriff provides court protection, county jail administration, and coroner service for all of the county and provides patrol and detective services for the unincorporated areas of the county. Placerville, population 11,000, has a municipal police department, as does South Lake Tahoe, population 22,000.
James Hume (18 Feb 1850- 7 Nov 1852)
Steven Charles Austin (7 Nov 1852- 7 Nov 1856)
William Tanner Henson (7 Nov 1856- 15 Sep 1859) - Resigned
Walter J. Burwell (15 Sep 1859- 15 Aug 1863) - Resigned
Henry Gooding (15 Aug 1863- 7 Nov 1867)
Jacob Hart Neff (7 Nov 1867- 7 Nov 1871)
Charles Benjamin Dunnam (7 Niv 1871- 7 Nov 1875)
Jason McCormick (7 Nov 1875- 7 Nov 1881)
George Burnham (7 Nov 1881- 7 Nov 1883)
Thomas Augustus Galt (7 Nov 1883- 7 Nov 1887)
George H. Hilbert (7 Nov 1887- 7 Nov 1898)
Archie Speer Bosquit (7 Nov 1898- 7 Nov 1907)
Gilbert Cook (7 Nov 1907- 9 May 1912) - Suicide
Albert George Bradshaw (9 May 1912- 7 Nov 1914)
Charles E. Hand (7 Nov 1914- 7 Nov 1925)
Charles F. Woods (7 Nov 1925- 7 Nov 1931)
George Martin Smith Sr. 7 Nov 1931- 7 Nov 1941)
Lowell Fred West (7 Nov 1941- 7 Nov 1949)
Rowland Lee Morris (7 Nov 1949- 7 Nov 1955)
Ernie Carlson (7 Nov 1955- 7 Nov 1965)
Robert Mitchum (7 Nov 1965- 7 Nov 1971)
Ernie Carlson (7 Nov 1971- 7 Nov 1975)
Al Coombs (7 Nov 1975-7 Nov 1977)
Richard "Dick" Pacileo (7 Nov 1977- 7 Nov 2001)
Jeff Neves ( 7 Nov 2001- 7 Nov 2010)'
John D'Agostini (7 Nov 2010- )
According to the U.S. Census Bureau, the county has a total area of 1,786 square miles (4,630 km2), of which 1,708 square miles (4,420 km2) is land and 78 square miles (200 km2) (4.4%) is water.
The county, owing to its location in the Sierra Nevada, consists of rolling hills and mountainous terrain. The northeast corner is in the Lake Tahoe Basin (part of the Great Basin), including a portion of the lake itself. Across the Sierra crest to the west lies the majority of the county, referred to as the “western slope.” A portion of Folsom Lake is in the northwest corner of the county.
Much of the county is public land. The Eldorado National Forest comprises a significant portion (approximately 43%) of the county's land area, primarily on the western slope. The Lake Tahoe Basin Management Unit, formerly part of the Eldorado and two other National Forests, manages much of the land east of the crest. The Pacific Crest Trail runs through the eastern part of the county, along or roughly paralleling the Sierra crest. The county is home to the Desolation Wilderness, a popular destination for hiking, backpacking, and fishing.
There were 58,939 households out of which 34.2% had youngsters under the age of 18 living with them, 60.1% were married couples living together, 8.9% had a female householder with no husband present, and 27.0% were non-families. 20.1% of all households were made up of individuals and 7.3% had someone living alone who was 65 years of age or older. The average household size was 2.63 and the average family size was 3.04.
In the county, the population was spread out with 26.1% under the age of 18, 6.8% from 18 to 24, 27.8% from 25 to 44, 26.9% from 45 to 64, and 12.4% who were 65 years of age or older. The median age was 39 years. For every 100 females, there were 99.5 males. For every 100 females age 18 and over, there were 97.3 males.
The 2000 census also states that the median income for a household in the county was $51,484, and the median income for a family was $60,250. Males had a median income of $46,373 versus $31,537 for females. The per capita income for the county was $25,560. About 5.0% of families and 7.1% of the population were below the poverty line, including 7.6% of those under age 18 and 5.0% of those age 65 or over.
The county is noted as a center of political concern with the United Nations non-binding sustainable development plan Agenda 21, which was on the County Board of Supervisors meeting Agenda on May 15, 2012. Concerns included the threat of U.S. Forest Service road closures and traffic roundabouts. On February 19, 2013, 14 members of the El Dorado County Grand Jury resigned, forcing Supervising Judge Steven Bailey to dissolve it.
Portions of El Dorado County are known to contain natural asbestos formations near the surface. The USGS studied amphiboles in rock and soil in the area in response to an EPA sampling study and subsequent criticism of the EPA study. The study found that many amphibole particles in the area meet the counting rule criteria used by the EPA for chemical and morphological limits, but do not meet morphological requirements for commercial-grade-asbestos. The executive summary pointed out that even particles that do not meet requirements for commercial-grade-asbestos may be a health threat and suggested a collaborative research effort to assess health risks associated with naturally occurring asbestos.
In 2003 after construction of the Oak Ridge High School (El Dorado Hills) soccer field, the federal Agency for Toxic Substances and Disease Registry found that some student athletes, coaches and school workers had received substantial exposures. The inside of the school needed to be cleaned of dust.