About 94546 - Castro Valley, California
The ZIP code 94546 of Castro Valley falls within California, the United States - a densely populated area by population. It sits within Alameda County.
Castro Valley has a reported population of 44,855. That's noticeably above the average for a California ZIP code, which sits near 22,296 people.
Population density runs around 1,085 people per sq. mile, making it a suburban area.
Other ZIP code codes in California serve areas such as Fontana, Pittsburg, Los Angeles.