Alpine is a census-designated place (CDP) in San Diego County, California. Alpine had a population of 14,236 at the 2010 census, up from 13,143 at the 2000 census. Alpine is the residence of former United States Representative Duncan Hunter. Major League Baseball Second baseman Marcus Giles lives there. The community's name was suggested by a resident of the area in the 1880s who believed that the environment was similar to her native home in Switzerland.

El Cajon; Iis a city in San Diego County, California. Nestled in a valley surrounded by mountains, the city has acquired the nickname of "The Big Box". Its name originated similarly, from the Spanish phrase "el cajón", which means "the big box" or "the drawer."

With the cession of California to the United States following the Mexican-American War, the 1848 Treaty of Guadalupe Hidalgo provided that the land grants would be honored. As required by the Land Act of 1851, a claim for Rancho El Cajon was filed by Thomas W. Sutherland, guardian of Pedrorena's heirs (his son, Miguel, and his three daughters, Victoria, Ysabel and Elenain) with the Public Land Commission in 1852, confirmed by the U.S. Supreme Court, and the grant was patented in 1876. In 1868, Los Angeles land developer Isaac Lankershim bought the bulk of the Pedrorena's Rancho El Cajon holdings and employed Major Levi Chase, a former Union Army officer, as his agent. Chase received from Lankershim 7,624 acres (30.9 km²) known as the Chase Ranch. Lankershim hired Amaziah Lord Knox (1833–1918), a New Englander whom he had met in San Francisco, to manage Rancho El Cajon. In 1876, Knox established a hotel there to serve the growing number of people traveling between San Diego and Julian, where gold had been discovered in 1869. Room and board for a guest and horse cost $1 a night. The area became known as Knox's Corners and was later renamed. By 1878 there were 25 families living in the valley and a portion of the hotel lobby became the valley post office with Knox as the first postmaster.

El Cajon was incorporated as a city in 1912.A portion of the western boundary of the city follows the eastern boundary of a similar land grant, made under Spanish law (prior to Mexican independence) to the Mission San Diego de Alcala.

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 upon 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. In August 1999 the plans for the Lakeside River Park was started in the San Diego River running through Lakeside. With the initial support of Eucalyptus Hills residents and overwhelming support of Lakeside citizens this was the start of a planned 52 mile long river park from the Pacific Ocean to the mountains. Many social and service groups are very active in Lakeside including VFW, Elks, Optimist, Soroptimist, 4-H, FFA, Boys and Girls Club, Boy Scouts, Girl Scouts, PLAY, United States Naval Sea Cadet Corps, youth soccer, baseball and football leagues, and the Cactus Park BMX track. The U.S. Navy maintains two large housing sites for military dependents in the town. Today, protection of the town's history falls to the Lakeside Historical Society, which works primarily to retain and preserve the buildings in the historic former downtown along Maine Avenue, now removed from the central business hub.

La Mesa is a city in Southern California, located in San Diego County. The population was 57,065 at the 2010 census, up from 54,749 at the 2000 census. Its civic motto is "the Jewel of the Hills."

La Mesa in Spanish means "the table", or alternately "the plateau", relating to its geography.La Mesa was part of a larger tract, Mission San Diego de Alcalá, and was used by Spanish Missionaries. 

La Mesa was founded in 1869 and The City of La Mesa was incorporated on February 16, 1912, under the general laws of the State of California. As such, it does not have a city charter but operates under the laws of the State of California in all respects not specifically covered by any city ordinance.

Its official flower is the bougainvillea.

Lemon Grove is a city in San Diego County, California. The population was 25,320 at the 2010 census, up from 24,918 as of the 2000 census. The large monument of a lemon pictured here has been its symbol since 1963.

The community was settled in 1869 by its first known permanent resident, sheep rancher Robert Allison. From the 1860s to 1900 the area was known for sheep and poultry ranching and vegetable crops. In the early 1900s, the community acquired its name when large citrus groves were planted, and lemon and orange growing and shipping became the area's major industry. The Lemon Grove Incident in 1931 was a boycott of segregated schools by Mexican Americans, resulting in the first court-ordered school desegregation in the United States. By World War II, most of the citrus groves had disappeared and suburbanization had begun. By 1960, most of the easily developable land was gone. Lemon Grove was incorporated as a general-law city in 1977; however, it continues to receive law enforcement services, via contract, from the San Diego County sheriff's office.

Santee is a suburban city in San Diego County, California, with a population of 53,413 at the 2010 census. Although it is a part of the East County region, Santee is located just 18 miles (29 km) from the Pacific Ocean. The city is connected to the coastline by State Route 52, a six-lane freeway that runs from Interstate 5 in La Jolla to State Route 67 in El Cajon. The city is bisected by the San Diego River, a linear greenbelt that includes parks, trails and more than 1,100 acres (450 ha) of natural riparian habitat. The city's potential for growth and progress was touted in a San Diego Union-Tribune editorial titled "All Roads Lead to Santee". Original inhabitants were the Kumeyaay Indians, who established a village on the banks of the San Diego River called Sinyeweche. The city is named after Milton Santee, second husband of Jennie Blodgett, whose first husband was George A. Cowles, a ranching pioneer in the San Diego area.

Spring Valley is a census-designated place (CDP) in San Diego County, California. The population was 28,205 at the 2010 census. The name "Spring Valley" may also refer to a wider area including the Spring Valley CDP, La Presa and part of the neighborhood of Casa de Oro (which extends into La Mesa). There are claims that the Greater Spring Valley area has over 100,000 residents although this claims large areas that are actually unincorporated parts of La Mesa and El Cajon.

Spring Valley is named for the natural spring located there. It was long the home of the Kumeyaay tribe, who called it Neti or Meti. Spanish conquerors drove off the natives and used the area for cattle, calling it El aguaje de San Jorge (St. George's Spring). In 1863 Judge Augustus S. Ensworth of San Diego filed a claim for a 160 acre (647,000 m²) ranch that included the spring. The ranch, and the small adobe house he built there, were sold to Rufus King Porter and later to historian Hubert Howe Bancroft. The adobe is now a National Historic Landmark