Lakeside is a census designated place (CDP) in San Diego County, California. The population was 20,648 at the 2010 census, up from 19,560 as of the 2000 census.
Lakeside was founded in 1886 when 6,600 acres of land surrounding the naturally occurring Lindo Lake were purchased by the El Cajon Valley Land Company, who immediately began to promote the new land as a town and built an 80-room Victorian-style inn, the Lakeside Hotel, at a cost of $50,000 (approximately $1,220,000 today). Three years later, in 1889, Lakeside became connected to the railroad system, and small businesses began to spring up, firmly establishing Lakeside as a bustling community. In 1904, John H. Gay bought the Lakeside Hotel and fenced off the park surrounding Lindo Lake, claiming both as part of his estate. He then proceeded to construct an automobile and horse racetrack around the lake, which became famous when Barney Oldfield set a new land speed record when visiting for the track's opening in 1907. The inn and racetrack became a popular gathering place for millionaires and celebrities and consistently drew large crowds by train to watch the races held there, but both were demolished per Gay's wishes at his death in 1920.
Lakeside has long held a reputation as a "cowboy town" and "rodeo town," due to the rural setting, the prevalence of ranches and the abundant horse ownership in the area, as well as hosting an 8-acre (32,000 m2) permanent rodeo facility, the Lakeside Rodeo Grounds. The venue is manned and maintained by the El Capitan Stadium Association, an all-volunteer group who aims to assist and support the youth of Lakeside by donating all proceeds from facility rentals to local sports and service, as well as education grants. Notable rodeos include the PRCA-sanctioned Lakeside Rodeo, part of their California circuit and usually occurring on the last weekend in April, regularly drawing over 20,000 observers to the arena, as well as the Lakeside Optimists' Bulls Only Rodeo in July.
During the middle of the 20th century, Lakeside was home to significant Native American, Spanish-speaking and Filipino populations.