The new county was created from parts of San Bernardino County and San Diego County. On May 2, 1893, seventy percent of voters approved the formation of Riverside County. Voters chose the city of Riverside as the county seat, also by a large margin. Riverside County was officially formed on May 9, 1893, when the Board of Commissioners filed the final canvass of the votes.
According to the U.S. Census Bureau, the county has a total area of 7,303 square miles (18,910 km2), of which 7,206 square miles (18,660 km2) is land and 97 square miles (250 km2) (1.3%) is water. It is the fourth-largest county in California by area. At roughly 180 miles (290 km) wide in the east-west dimension, the area of the county is massive. Riverside County, California is roughly the size of the State of New Jersey in total area.
The 2010 United States Census reported that Riverside County had a population of 2,189,641. The racial makeup of Riverside County was 1,335,147 (61.0%) White (40.7% Non-Hispanic White), 140,543 (6.4%) African American, 23,710 (1.1%) Native American, 130,468 (6.0%) Asian (2.3% Filipino, 0.8% Chinese, 0.7% Vietnamese, 0.6% Korean, 0.5% Indian, 0.2% Japanese, 0.1% Cambodian, 0.1% Laotian, 0.1% Pakistani), 6,874 (0.3%) Pacific Islander, 448,235 (20.5%) from other races, and 104,664 (4.8%) from two or more races. Hispanic or Latino of any race were 995,257 persons (45.5%); 39.5% of Riverside County is Mexican, 0.8% Salvadoran, 0.7% Honduran, 0.6% Puerto Rican, 0.3% Cuban, and 0.2% Nicaraguan.
Riverside County has 12 federally recognized Indian reservations, which ties it with Sandoval County, New Mexico for second most of any county in the United States. (Sandoval County, however, has two additional joint-use areas, shared between reservations. San Diego County, California has the most, with 18 reservations.)
The median income for a household in the county was $42,887, and the median income for a family was $48,409. Males had a median income of $38,639 versus $28,032 for females. The per capita income for the county was $18,689. About 10.7% of families and 14.2% of the population were below the poverty line, including 18.5% of those under age 18 and 7.6% of those age 65 or over.
