Diamond Bar is a city in Los Angeles County, California, United States. The population was 56,287 at the 2000 census. It is named after the "diamond over a bar" branding iron registered in 1918 by ranch owner Frederick E. Lewis.
Located at the junction of the Pomona and Orange Freeways, Diamond Bar is primarily a residential city with shopping centers interspersed within the city. The city features a public Los Angeles County golf course.
As with most Southern California cities, more modest housing is located closer to freeways and main roads, while upscale housing is located mostly in hilly terrain. The Country, a gated hillside enclave of 751 multi-million dollar estate residences, was developed in the 1970s.
On March 30, 1840 Jose de la Luz Linares founded the Rancho Los Nogales (Ranch of the Walnut Trees) on a Mexican land grant of 4,340 acres (18 km²) deeded to him by Governor Juan Alvarado, which included Brea Canyon and the eastern Walnut Valley.
As time wore on - and particularly as the United States government took over California - Rancho Los Nogales was divided and sold into multiple land ranches, the largest of which was the Diamond Bar Ranch. At the time, it was one of the largest working cattle ranches in the western U.S.
The entire Diamond Bar Ranch was acquired by the Transamerica Corporation in the 1950s for the purpose of developing one of the nation's first master-planned communities. Transamerica gave the Diamond Bar name to its new community and incorporated the ranch's familiar diamond and bar cattle brand into various logos (many of which are still in use today).
Transamerica oversaw all development of the community through the 1960s. The Transamerica Corporation divested itself of all its real estate ventures in the 1970s and 1980s. As a result, the Diamond Bar project was sold to multiple developers and much of its initial master plan was not implemented during the latter half of its development in the 1980s.
Diamond Bar City Council is currently headed by Mayor Steve Tye and Mayor Pro Tem Jack Tanaka. The remaining three council members are Wen Chang, Bob Zirbes, and Carol Herrera. Bob Zirbes has since died from a battle with cancer.
Diamond Bar has several elementary, junior high, and high schools. The city is divided into two school districts. Those south of Grand Ave are part of the Walnut Valley Unified School District and in the northern portion are part of the Pomona Unified School District.
Schools in the Pomona Unified:
Armstrong Elementary School
Diamond Point Elementary
Golden Springs Elementary
Lorbeer Middle School
Diamond Ranch High School
Schools in the Walnut Valley Unified:
Castle Rock Elementary
Maple Hill Elementary
Quail Summit Elementary
Chaparral Middle School
South Pointe Middle School
Diamond Bar High School