Diamond Bar highlight
Master-planned hillside community
One of the nation's first master-planned communities, with the first houses built in 1959 and incorporated as a city in 1989.
Diamond Bar began development as a master-planned residential community in 1959 when the first houses were built in what would become a 22-square-mile municipality. The name comes from the diamond-bar cattle brand, registered in 1918 by ranch owner Frederic E. Lewis, and the community developed by the Transamerica Corporation as one of the nation's pioneering planned communities, where residential areas were intentionally designed with neighborhood centers, schools, and commercial districts in mind.
The city incorporated officially on April 18, 1989, after thirty years as an unincorporated community in Los Angeles County. Located about 27 miles east of downtown Los Angeles in the San Gabriel Valley, Diamond Bar's hillside terrain shaped its layout, with streets following the contours of the land and creating distinct residential neighborhoods. The median household income in the city is $106,602, reflecting the professional and business families who chose Diamond Bar as a place to establish their households.
Planned communities were built with the long term in mind, and families who choose to build their futures here make similar decisions about time horizons and commitments. A term life insurance policy chosen to match the years until a mortgage is paid off or children finish school is part of that same planning frame: using the years you can predict to secure the years you cannot.