Napa County is a county in California, United States, about 50 miles northeast of San Francisco across San Pablo Bay. It had a population of 138,019 at the 2020 census, an estimated 134,869 by 2024, and covers 748 square miles (1,940 km2) of land centred near 38°30′N 122°19′W.
Napa is the county seat and the county’s only city with over 50,000 residents; its postal code is 94559. The county holds 5 cities and 7 unincorporated communities across the Napa Valley wine region, and it runs on Pacific Time. Its FIPS code is 06055.
Towns & Villages in Napa County
Napa County has 12 named places: 5 incorporated cities and 7 census-designated places (CDPs), all but one of them strung along the Napa Valley floor between the Mayacamas and Vaca mountain ranges. California has no civil townships, so the table below drops that column.
| Place | Type | Pop. | ZIP |
|---|---|---|---|
| Napa | City · seat | 76,915 | 94558, 94559, 94581 |
| American Canyon | City | 21,837 | 94503 |
| St. Helena | City | 5,430 | 94574 |
| Calistoga | City | 5,228 | 94515 |
| Yountville | City | 3,436 | 94599 |
| Angwin | CDP | 2,633 | 94508 |
| Deer Park | CDP | 1,294 | 94576 |
| Silverado Resort | CDP | 948 | — |
| Moskowite Corner | CDP | 237 | — |
| Rutherford | CDP | 115 | 94573 |
| Oakville | CDP | 49 | 94562 |
Rutherford and Oakville sit only two miles apart on Highway 29 and both take their names from 19th-century vineyard families — do not confuse them with the wine appellations of the same name, which run wider than the CDP boundaries. Circle Oaks, in the hills northeast of the valley, is an unincorporated community but not a Census-recognized CDP, so it has no row here.
ZIP Codes
- 94558, 94559, 94581 — Napa (also serves the unincorporated Napa Valley floor south of the city)
- 94503 — American Canyon
- 94574 — St. Helena
- 94515 — Calistoga
- 94599 — Yountville
- 94508 and 94576 — Angwin and Deer Park (Angwin uses both; Deer Park is served by 94576)
- 94573 — Rutherford
- 94562 — Oakville
Silverado Resort and Moskowite Corner have no ZIP code of their own; mail there is routed through Napa’s 94558.
Geography
Napa County runs along the Napa River valley between the Mayacamas Mountains to the west and the Vaca Mountains to the east, narrowing from a wide agricultural floor near American Canyon to a steep, forested northern tip above Calistoga. The county’s southern edge meets San Pablo Bay, the northern arm of San Francisco Bay, giving it tidal marsh and open water along with its vineyard land. Lake Berryessa, the county’s largest lake, sits in the eastern hills behind Monticello Dam.
Napa County borders Sonoma County to the west, Lake County to the north, Yolo County to the northeast, and Solano County to the southeast. Marin County lies across San Pablo Bay to the south but shares no confirmed land border with Napa County, so it is not listed as an adjoining county here.
Demographics
The county’s population was 138,019 at the 2020 census, easing to an estimated 134,869 by 2024. Napa, the county seat, is by far the largest community, followed by American Canyon; together the two hold more than 70 percent of the county’s residents. Median household income was $111,471 in 2024, above both the statewide and national medians. Population density works out to roughly 185 people per square mile of land, concentrated in the valley towns rather than the surrounding hills.
Economy & Local Life
Wine drives the county’s economy: more than 400 wineries operate across the Napa Valley AVA, drawing an estimated 4.5 to 5 million visitors a year. Health care and social assistance is the single largest employment sector (9,480 workers in 2024), followed closely by manufacturing, most of it winemaking and bottling (8,704 workers). Major named employers include the Napa Valley Unified School District and County of Napa in the city of Napa, Trinchero Family Estates and Beringer Vineyards in St. Helena, and Owens Corning and Mezzetta in American Canyon. The Culinary Institute of America at Greystone, in St. Helena, and Yountville’s French Laundry — twice named the world’s best restaurant — anchor the county’s culinary reputation. The Napa Valley Wine Auction, held each June, is the county’s best-known annual event.
History
Napa County was one of California’s original 27 counties, established February 18, 1850, at statehood. Its name comes from the city of Napa and is generally traced to a Patwin word, though its exact meaning is disputed. Vineyards were planted commercially from the 1860s onward, and by 1880 the county already counted 443 vineyard operations. The 1976 “Judgment of Paris” blind tasting, where a Stag’s Leap Wine Cellars cabernet and a Chateau Montelena chardonnay beat top French wines, put Napa Valley on the world wine map.
More recently, wildfire has repeatedly hit the county. The October 2017 Atlas, Tubbs and Nuns fires together destroyed thousands of structures and killed 31 people across Napa and Sonoma counties, with the Atlas Fire alone burning north of the city of Napa. The Glass Fire, starting September 27, 2020, burned 67,484 acres and destroyed 1,555 structures, including 308 homes and 343 commercial buildings in Napa County; it forced roughly 70,000 evacuations across both counties and destroyed the Foothills Adventist Elementary School in Deer Park before full containment on October 20, 2020. No deaths were reported from the Glass Fire. PG&E opened the Calistoga Resiliency Center, a hydrogen-fuel-cell microgrid, in 2024 to keep the city powered through future fire-season shutoffs.
Getting There
No interstate highway crosses Napa County; State Route 29 is the main north-south corridor through the valley, with State Routes 12, 121 and 128 crossing it at various points. Distances from Napa:
- San Francisco — 46 miles south
- Sacramento — 55 miles northeast
- Santa Rosa — 20 miles west
- Vallejo — 15 miles south
The nearest commercial airports are Oakland International and San Francisco International, both about 45 to 50 miles south. The nearest Amtrak service is the Capitol Corridor’s Martinez station, roughly 25 miles south via State Route 29 and I-80.
Frequently Asked Questions
Where is Napa County?
It is in Northern California’s Wine Country, about 50 miles northeast of San Francisco, bordered by Sonoma, Lake, Yolo and Solano counties.
What is the population of Napa County?
138,019 at the 2020 census, estimated at 134,869 in 2024.
How big is Napa County?
748 square miles (1,940 km2) of land, plus about 40 square miles of San Pablo Bay water.
What is the county seat of Napa County?
Napa is the county seat, with a 2020 population of 76,915.
How many towns are in Napa County?
Five incorporated cities — Napa, American Canyon, St. Helena, Calistoga and Yountville — plus seven census-designated places including Angwin and Rutherford.
What ZIP codes cover Napa County?
Napa uses 94558, 94559 and 94581; the other cities each have their own code, from 94503 (American Canyon) to 94599 (Yountville).
Did wildfires damage Napa County?
Yes. The 2017 Atlas Fire and the 2020 Glass Fire both burned across the county, destroying homes, wineries and the Foothills Adventist Elementary School in Deer Park.
More counties in this state: Towns and villages in California.