Agriculture in the prehistoric Southwest
After the Hohokam disappeared, Spanish explorers of the 16th century noted the use of canal irrigation in only two areas of the Southwest: eastern Sonora, primarily practiced by the Opata and Lower Pima, and among the Pueblos of northern New Mexico. Irrigation by the Opata and Pueblos had different objectives. In Sonora, with a long growing season, two crops of maize a year were grown in river valleys. The spring crop during the dry season was dependent upon irrigation; the summer and fall crop during the rainy season utilized irrigation to supplement rainfall. The necessity of irrigation probably required a high level of social organization. In New Mexico, with only one crop of maize per year possible, irrigation was supplemental and the lesser dependence on irrigation implies less social organization than in Sonora.
Alhambra Creek
Beginning some 8,000 years ago, Native Americans (Miwok and Costanoan), hunted, fished and gathered food in the interior rolling hills and wetlands associated with Alhambra Creek. The use of intentionally set wildland fires became a common practice to maximize the land's productivity for hunting and seed gathering. However, by the late 18th century this way of life began to fade as the first waves of Spanish settlers moved into the Bay Area. This was the beginning of 200 years of rapid change, as the entire Bay Area transformed from a sparsely populated native landscape to a highly manipulated, densely populated urbanized setting. Arroyo del Hambre (Alhambra Creek) and its tributaries lie within the boundaries of two large Mexican Land Grants that were established in the early to mid-19th century. The city of Martinez at the mouth of the watershed was part of Rancho Pinole owned by the Martinez family. A large tidal wetland at the mouth of the creek still exists today although it is significantly reduced in size. The city was founded in 1849 on along the creek's floodplain and it has experienced numerous mild to severe seasonal flooding events ever since. Further up the watershed, the Briones family owned the Briones Valley Rancho (1852 land grant) a portion of which in modern times became the Briones Regional Park of . Cattle ranching was the predominant land use in the watershed during the early years of settlement followed by establishment of orchards and vineyards in the richer soils of Alhambra Valley. By 1920, an average of 150 carloads of pears, 30 cars of grapes and 20 cars of apricots and plums were sent out annually, making Alhambra Valley one of the largest commercial pear orchards of its time.