San_Gabriel_Valley

The San Gabriel Valley (Spanish: Valle de San Gabriel), often referred to by its initials as SGV, is one of the principal valleys of Southern California, with the city of Los Angeles directly bordering it to the west, and occupying the vast majority of the southeastern part of Los Angeles County. Surrounding landforms and other features include the following:

the San Gabriel Mountains to the north;
the San Rafael Hills to the west, with the Los Angeles Basin beyond;
the Crescenta Valley to the northwest;
the Puente Hills to the south, with the coastal plain of Orange County beyond;
the Chino Hills and San Jose Hills to the east, with the Pomona Valley and Inland Empire beyond; and
the city limits of Los Angeles, bordering its western edge.The San Gabriel Valley derives its name from the San Gabriel River that flows southward through the center of the valley, which itself was named for the Spanish Mission San Gabriel Arcángel originally built in the Whittier Narrows in 1771.
Once predominantly agricultural, the San Gabriel Valley today is almost entirely urbanized and is an integral part of the Greater Los Angeles metropolitan area. It is one of the most ethnically diverse regions in the country. Covering about 200 sq mi (520 km2) in area, the valley includes 31 cities and five unincorporated communities. It is located entirely within Los Angeles County.
Pasadena is the largest city in the San Gabriel Valley. Pasadena was incorporated in 1886, making it the fourth city incorporated in Los Angeles County, following Los Angeles, Santa Ana, and Anaheim (Santa Ana and Anaheim are both now located in Orange County, which broke off in 1889). More recently, statewide droughts have further strained the San Gabriel Valley's and Los Angeles County's water security.