Walnut is a city in Los Angeles County, California, in the United States. The city had a population of 29,172 according to the 2010 census, and the population in 2019 was expected to be 29,685.
The broader Walnut Valley is bounded to the north by the steep San Jose Hills mountain range and to the south by the mild Puente Hills. Master-planned single-family houses ranging in size from 1,800 to 11,200 square feet constitute quality housing (170 to 1,040 m2). The Walnut Valley Unified School District, which has been regarded as one of the top public school systems in Southern California by multiple sources, as well as Mt. San Antonio College, are located in the city. Walnut has one of the lowest crime rates in the San Gabriel Valley. 
The name of the city is derived from the Rancho Los Nogales Mexican land grant, with nogales being the Spanish word for “walnut trees”; the native California black walnut is a common tree in the San Jose Hills. Walnut is a general law city that was founded on January 19, 1959. It is governed by a city council/city manager system. Residents elect a five-member city council, and the council elects a mayor every year for a twelve-month term. The council appoints a city manager to handle the city’s daily operations.
The Tongva people’s traditional homeland are located here. The indigenous Gabrieleo were so named by Spanish missionaries who arrived in the 18th century because the area where they lived was administered by the San Gabriel Mission. The Walnut region was part of the Mission’s network of outlying ranches utilized for cattle and sheep grazing.
Following the secularization of the missions in the 1830s, the Mexican government of Alta California partitioned former mission holdings into ranchos and distributed them as land concessions. Rancho San Jose (given to Ricardo Vejar and Ygnacio Palomares in 1837); Rancho Los Nogales (issued to Jose De La Cruz Linares in 1840); and Rancho La Puente (provided to Jose De La Cruz Linares in 1840) were the first gifts in the Walnut area (granted to John Rowland and William Workman in 1842). In 1868, John Rowland and William Workman split Rancho La Puente, with Rowland retaining the eastern half and Workman retaining the western half. Rowland’s property covered the western portion of Walnut as well as the nearby town currently known as Rowland Heights. The property was mostly utilized for cattle breeding and the cultivation of wheat, vineyards, and fruit trees (mostly citrus).
The first US post office, named “Lemon,” was founded in 1895. The name of the post office was changed to Walnut in 1908. The United States Post Office is located on Lemon Avenue, one of the town’s principal streets, as a remembrance of those early days.
As Walnut’s bicentennial project, the City of Walnut’s Bicentennial Commission chose the creation of Lemon Creek Park and the restoration of the William R. Rowland Adobe Redwood Ranch House. Sheriff William Rowland received the 29,000-acre (120 km2) ranch from his father, John Rowland, in 1872, and the Lemon Creek Park region became his property. Mr. Meridith, ranch foreman for William Rowland, lived in the small building built in 1883. The adobe redwood ranch house is one of the area’s few existing ranch style redwood and adobe houses. The W.R. Rowland ranch home was added on the National Register of Historic Places on October 1, 1975, by the State Landmark Committee.
Next Neighborhood: Blackstone / Olinda Ranch