530 Area Code: Chico, California

Set across northern California's interior — the upper Sacramento Valley, the Sierra Nevada foothills, and a long stretch of the state's mountainous northeast — the 530 area code carries phone numbers across some of the geographically largest territory of any California code. Chico, in the foothills west of the Sierra, anchors the directory's records here. The city sits along Big Chico Creek where the valley floor meets the rising terrain toward Lassen Volcanic National Park, and its working profile is built around California State University, Chico, agricultural processing, and a long-running role as the regional commercial center for several rural counties.

Other California cities — Anaheim, Bakersfield, Concord, Daly City, and others — turn up in the directory's records tied to 530 numbers. None of those are inside 530's footprint. Their recurrence is a function of California's high inter-city number mobility and of the routine ways porting, registration, and address linkages spread records across the state. The directory currently tracks 522 distinct prefixes within 530 in detail, a working subset of the prefix population actually carried by the code.

Chico's median age is the most striking demographic feature: at the very low end of the early thirties, it sits well below the US figure, a pattern driven heavily by the university student population. Household income runs below the national reading, home values come in well above the US median in line with broader California costs, and the city's population is modest in absolute terms but among the largest in the state's far north.