Data Last Updated: July 1, 2025

The ZIP Code, Map and Demographics of Duncans Mills, CA

95430 is the only ZIP Code for Duncans Mills, CA
Enter an Address to find the ZIP+4: The ZIP+4 code is an extension of the five-digit ZIP code used by the USPS. The four extra digits are added after a hyphen to the standard five-digit ZIP code. The ZIP+4 code identifies a specific geographic segment within the five-digit delivery area, such as a city block, a group of apartments, or a post office box. The ZIP+4 code can also indicate the side of the street on which a building is located.

Using the full ZIP code with the extra four digits when mailing via the USPS ensures the fastest, most accurate mailing possible. The ZIP+4 code enables mail to arrive faster, as it reduces the need for human interaction in a mail center.

The ZIP+4 code is also known as a "plus-four code", "add-on code", or "add-on". and ensure faster mail delivery, or check out the Demographic Profile.

ZIP Code: Duncans Mills, CA has only 1 PO Box ZIP assigned to it by the U.S. Postal Service.	95430 (PO Box)
County: The County, Parish, Borough, or Planning Region that ZIPs in Duncans Mills, CA at least partially reside in. These can be completely inside the County, or they can cross into several Counties.	Sonoma County, CA
Area Codes: Telephone Area Codes that are associated with Duncans Mills, CA. These are used in the North American Numbering Plan (NANP) to facilitate phone routing.	369, 707
Time Zone: Time zone designation. Please note that not all areas in the U.S. observe daylight saving time which can affect actual local time.	Pacific (GMT -08:00)
Local Time: The current local time for Duncans Mills, CA. If more than 1 time zone for this area, all local times will be shown. Keep in mind that areas can cross time zones, so more than 1 may be shown.	12:00:00 AM
Population of ZIP Code: The population of the ZIP which covers the Duncans Mills, CA area. These are usually small towns or a collection of small towns, but the USPS groups them together for the delivery of mail.	45 [More Details]
Statistical Area: A Core Based Statistical Area (CBSA) is the recognized term for a region that functions around an urban core with a population of at least 10,000 people, according to the standards set by the Office of Management and Budget (OMB).	Santa Rosa-Petaluma, CA
Coordinates: The latitude/longitude centroid coordinates for this area.	38.4471, -123.0686
Land Area: The approximate amount of land area covered by all ZIPs for Duncans Mills, CA in square miles. The Land Area is based on geographic boundaries that include the mainland, islands, inland, coastal, Great Lakes, and territorial waters associated with each geography.	0.24 sq miles (ZIP Code)
Quick Link: Copy the direct link to the Duncans Mills, CA page and use anywhere you like!	https://www.zip-codes.com/city/ca-duncans-mills.asp

Download ZIP Code Database

Duncans Mills, CA ZIP Code Map

Duncans Mills, CA Demographic Profile

Population & People

Total Population

More | See by Race

Income

Median Household Income

See Chart

Housing

Total Housing Units

Health

Without Healthcare Coverage

See Chart

Business & Economy

Total Businesses

Families

Total Households

Employment

Employment Rate

See Chart

Education

Bachelor's Degree or Higher

Important Duncans Mills, CA Information

Duncans Mills, CA has 0 Standard (Non-Unique) and 1 PO Box ZIP Codes. Together, these cover a total of 0.24 square miles of land area and 0.13 square miles of water area.

The population for the ZIP Code is 45. Average Household Size is 1.80 persons and Average Family Size is 2.37 persons.. More Demographics are available below, including charts showing racial comparison, gender breakdown, population over time, average income, average house value, income over time, and more.

Sonoma County is the only county which covers this area. There are 2 area codes serving this area including 369 and 707. Duncans Mills is also located in the Pacific (GMT -08:00) timezone and the current local time is shown above.

Duncans Mills is part of the Santa Rosa-Petaluma, CA Core Based Statistical Area (CBSA). Its CBSA Code is 42220.It is classified as a metro area, which means the combined population is 50,000 or more (at its core).

CBSAs are defined by the OMB as geographic areas that have at least one core with a population of 10,000 or more (for a micro area) and adjacent territory with a high degree of social and economic integration. CBSA codes are commonly used to accurately file Medicare claims and to verify applicable incentives using a patient's ZIP Code.

There are 18 businesses with a total of 86 employees. That is an average of 4.8 employees per business. Annual payroll for these businesses is $3,360,000. Other Demographics

Duncans Mills, CA has 1 ZIP Code

ZIP Code	Type	Population	% of Population	Alias Names
95430	P.O. Box	45	100.00%

Duncans Mills, CA Demographic Information

Data labeled as "All ZIP Codes" is a total (or average) for every ZIP Code in Duncans Mills, CA. The U.S. Postal Service provides a name (and aliases) for every ZIP Code which can include cities, towns, villages, and other incorporated names.

There is currently no matching U.S. Census Place for this geographic area. Many rural areas may have such low population density that they will not be part of any U.S. Census Place.

Total Population: Total number of people from the 2020 U.S. Census for all ZIPs in Duncans Mills, CA. This reflects the exact count of this area at that point in time, not future estimates, regardless of citizenship or immigration status. It is intended to count all persons living within the geographic area, not just those present on the day of the census.	45
Total Households: Total number of Households from the 2020 U.S. Census for all ZIPs in Duncans Mills, CA. A Household includes everyone living in a residential housing unit. This includes families, roommates in a single residence, or a person living alone.	25
Total Housing Units: The total number of Housing Units is the number of occupied units + the number of vacant units. Ownership is defined by whether the unit is occupied by an owner or by a tenant. Owner occupancy means that the owner lives in the unit. This value comes from the 2020 U.S. Census and is not a projection or estimate.	28
Average Household Size: The Average Household Size, is obtained by dividing the number of people in Households (excluding those in group quarters, nursing home, prisons, and dorm rooms) by the number of Households. A Household includes everyone living in a residential unit. Those who do not live in a household are classified as living in group accommodation. This value is an estimate from the U.S. Census ACS (American Community Survey) and is updated yearly.	1.80
Average Family Size: Average Family Size is calculated by dividing the number of people in a Family Household by the number of Family Households. The U.S. Census Bureau defines family households as households consisting of two or more individuals who are related by birth, marriage, or adoption. They also may include other unrelated people. Non-family households consist of people who live alone or who share their residence with unrelated individuals. The Average Family Size only looks at the households classified as Family Households. This value is an estimate from the U.S. Census ACS (American Community Survey) and is updated yearly.	2.37

All ZIP Codes assigned this City name by the USPS.

Pie Chart & Table (ZIPs)Comparison Chart

Population by Race

White: The number of individuals who selected White as their race is an exact count from the 2020 Census for this geographic area. On the 2020 U.S. Census questionnaire, people were asked to check all races which applied to them, including White. This count includes all who selected White/Caucasian in their response, even if they selected another race as well.	44	100.00%
Black: The number of individuals who selected Black as their race is an exact count from the 2020 Census for this geographic area. On the 2020 U.S. Census questionnaire, people were asked to check all races which applied to them, including Black or African American. This count includes all who selected Black or African American in their response, even if they selected another race as well.	0	0%
Hispanic: The number of individuals who selected Hispanic is an exact count from the 2020 Census for this geographic area. On the 2020 U.S. Census questionnaire, people were first asked for their Ethnicity, including if they were from Hispanic, Latino, or Spanish Origin, including Mexican, Mexican American, Chicano, Puerto Rican, Cuban, or other ethnic origin. This count includes all who affirmed that they were part of this ethnic origin. Respondents who selected this option were also asked to select a race separately and would be counted once in this number as well as the race they chose. From the U.S. Census definition, Hispanic is an ethnic origin and not a race.	0	0%
Asian: The number of individuals who selected Asian as their race is an exact count from the 2020 Census for this geographic area. On the U.S. Census questionnaire, people were asked to check all races which applied to them, including Chinese, Filipino, Asian Indian, Vietnamese, Korean, Japanese, or Other Asian. This count includes all who selected one of these options in their response, even if they selected another race as well.	0	0%
American Indian: The number of individuals who selected American Indian and Alaska Native as their race is an exact count from the 2020 Census for this geographic area. On the 2020 U.S. Census questionnaire, people were asked to check all races which applied to them, including American Indian and Alaska Native. This count includes all who selected American Indian and Alaska Native in their response, even if they selected another race as well.	0	0%
Hawaiian: The number of individuals who selected Hawaiian or Pacific Islander as their race is an exact count from the 2020 Census for this geographic area. On the 2020 U.S. Census questionnaire, people were asked to check all races which applied to them, including Native Hawaiian and Pacific Islander. This count includes all who selected either Hawaiian or Pacific Islander in their response, even if they selected another race as well.	0	0%
Other: The number of individuals who selected Other as their race on the 2020 Census. On the 2020 U.S. Census questionnaire, people were asked to check all races which applied to them, and this includes all individuals who did not select one of the races above.	0	0%

All ZIP Codes assigned this City name by the USPS.

Pie Chart showing Population by Race: White [44, 100.00%], Black [0, 0%], Hispanic [0, 0%], Asian [0, 0%], Hawaiian [0, 0%], American Indian 0, 0%], and Other [0, 0%] for all ZIPs in Duncans Mills, California. Load Chart

Source: U.S. Census Bureau (2020) DHC

Pie Chart & Table (ZIPs)Comparison Chart

Gender Breakdown

Males: The # of Males from the 2020 Census. This is not a forecast for the future, but an exact count for this geographic area at the time of the Census. Each respondent self-identified their gender on the survey, as they were asked to indicate their gender assigned at birth. This information is important for healthcare planning, policy making, social research, and economic planning and development.	26	57.78%
Females: The # of Females from the 2020 Census. This is not a forecast for the future, but an exact count for this geographic area at the time of the Census. Each respondent self-identified their gender on the survey, as they were asked to indicate their gender assigned at birth. This information is important for healthcare planning, policy making, social research, and economic planning and development.	19	42.22%
Median Age: The Median Age of all persons from the 2020 Census for this geographic area. Median age is the middle age of the population. Half the people are older than the average age and half area younger. Median Age can relate how young or old a geographic area is compared to others.		55.8 years
Male Median Age: The Median Age of all Males from the 2020 Census for this geographic area. The Male Median Age is the actual average from the 2020 Census, not an estimate or future projection. Median Age is the average age of the population. Half of the population is older and the other half is younger. Gender is self-reported by individuals when asked about their sex at birth.		64.0 years
Female Median Age: The Median Age of all Females from the 2020 Census for this geographic area. The Female Median Age is the actual average from the 2020 Census, not an estimate or future projection. Median Age is the average age of the population. Half of the population is older and the other half is younger. Gender is self-reported by individuals when asked about their sex at birth.		39.5 years

All ZIP Codes assigned this City name by the USPS.

Pie Chart showing population of Males [26, 57.78%] vs Females [19, 42.22%] for all ZIPs in Duncans Mills, California. Load Chart

Source: U.S. Census Bureau (2020) DHC

Population by Age & Gender

Median Age: The Median Age of the Total Population from the 2020 Census for this geographic area. Median age is the middle age of the population. Half the people area older than the average age and half are younger. Median Age can relate how young or old a geographic area is compared to others. 55.8

Male Median Age: The Median Age of all Males from the 2020 Census for this geographic area. The Male Median Age is the actual average from the 2020 Census, not an estimate or future projection. Median Age is the average age of the population. Half of the population is older and the other half is younger. Gender is self-reported by individuals when asked about their sex at birth. 64.0

Female Median Age: The Median Age of all Females from the 2020 Census for this geographic area. The Female Median Age is the actual average from the 2020 Census, not an estimate or future projection. Median Age is the average age of the population. Half of the population is older and the other half is younger. Gender is self-reported by individuals when asked about their sex at birth. 39.5

Line Chart showing the population by Age Group and Gender of all ZIPs in Duncans Mills, California. One line shows the Total population in that age group, another line shows the Male population for that age group, and the last line shows the Female population for the given age group. A table also provides the same information. Load Chart

Source: U.S. Census Bureau (2020) DHC

Group	< 5	5-9	15-19	20-24	30-34	35-39	45-49	50-54	55-59	60-64	65-69	75-79	80-84
Male	1	1	0	0	0	3	1	0	4	5	6	0	5
Female	3	1	2	1	2	1	1	4	1	1	0	1	1
Total	4	2	2	1	2	4	2	4	5	6	6	1	6

Average Income per Household

Bar Chart showing Average Income per Household for all ZIPs in Duncans Mills, CA, the U.S. Census Place, Sonoma County, the state of California, and the United States National Average. Load Chart

Source: U.S. Census 2019-2023 American Community Survey 5-Year Estimates. Table DP03. SELECTED ECONOMIC CHARACTERISTICS

Income Estimate Over Time

Line Chart showing Median Income Estimates from 2011 until 2023 of Median Household Income, Median Family Income, Median Nonfamily Income, Median Male Income, and Median Female Income for all ZIPs in Duncans Mills, California. A table also provides the same information. Load Chart

Source: U.S. Census 2011-2023 American Community Survey 5-Year Estimates. DP03. SELECTED ECONOMIC CHARACTERISTICS

Income Type	2011	2102	2013	2014	2015	2016	2017	2018	2019	2020	2021	2022	2023
Median Household Income	$0	$0	$0	$0	$0	$0	$0	$0	$0	$0	$0	$0	$0
Median Family Income	$0	$0	$0	$0	$0	$0	$0	$0	$0	$0	$0	$0	$0
Median NonFamily Income	$0	$0	$0	$0	$0	$0	$0	$0	$0	$0	$0	$0	$0
Median Male Income	$0	$0	$0	$0	$0	$0	$0	$0	$0	$0	$0	$0	$0
Median Female Income	$0	$0	$0	$0	$0	$0	$0	$0	$0	$0	$0	$0	$0

Average House Value

Bar Chart showing Average House Value for all ZIPs in Duncans Mills, California, the U.S. Census Place, Sonoma County, California, and the United States National Average. Load Chart

Source: U.S. Census 2019-2023 American Community Survey 5-Year Estimates. Table DP03. SELECTED ECONOMIC CHARACTERISTICS

Population Estimate Over Time

Line Chart showing Population Estimates from 2011 until 2023 for all ZIPs in Duncans Mills, California and Decennial U.S. Census lines for 2010 and 2020 actual population. A table also provides the same information. Load Chart

Source: U.S. Census 2011-2023 American Community Survey 5-Year Estimates. DP05. DEMOGRAPHIC AND HOUSING ESTIMATES

Group	2010	2011	2102	2013	2014	2015	2016	2017	2018	2019	2020	2021	2022	2023
Population Estimate	--	0	0	0	0	0	0	6	7	7	13	15	0	0
Decennial Census	44	--	--	--	--	--	--	--	--	--	45	--	--	--

Pie Chart & Table (ZIPs)Comparison Chart

Employment Status

Employed: Employed includes all civilians 16 years old and over who were either (1) "at work" -- those who did any work at all during the reference period as paid employees, worked in their own business or profession, worked on their own farm, or worked 15 hours or more as unpaid workers on a family farm or in a family business; or (2) were "with a job but not at work" -- those who did not work during the reference period but had jobs or businesses from which they were temporarily absent due to illness, bad weather, industrial dispute, vacation, or other personal reasons.	0	0%
Unemployed: All civilians 16 years old and over are classified as unemployed if they (1) were neither "at work" nor "with a job but not at work" during the reference period, and (2) were actively looking for work during the last 4 weeks, and (3) were available to accept a job. Also included as unemployed are civilians who did not work at all during the reference period, were waiting to be called back to a job from which they had been laid off, and were available for work except for temporary illness.	0	0%
Not In Labor Force: Not in labor force includes all people 16 years old and over who are not classified as members of the labor force. This category consists mainly of students, housewives, retired workers, seasonal workers interviewed in an off season who were not looking for work, institutionalized people, and people doing only incidental unpaid family work (less than 15 hours during the reference period).	0	0%

All ZIP Codes assigned this City name by the USPS.

Pie Chart showing Employment Status of those Employed [0, 0%], Unemployed [0, 0%], and Not In the Labor Force [0, 0%] for all ZIPs in Duncans Mills, CA. A table also provides the same information. Load Chart

Source: U.S. Census 2019-2023 American Community Survey 5-Year Estimates. Table DP03. SELECTED ECONOMIC CHARACTERISTICS

Gross Rent Paid

Less than $500: Gross rent is the monthly rent plus the estimated average monthly cost of utilities (electricity, gas, water and sewer) and fuels (oil, coal, kerosene, wood, etc.) fuels. This shows the number of renter-occupied units paying cash rent (excluding one-family houses on ten or more acres) and percentage which paid under $500 per month.	0	0%
$500 to $999: Gross rent is the monthly rent plus the estimated average monthly cost of utilities (electricity, gas, water and sewer) and fuels (oil, coal, kerosene, wood, etc.). This shows the number of renter-occupied units paying cash rent (excluding one-family houses on ten or more acres) and percentage which paid between $500 to $999 per month.	0	0%
$1,000 to $1,499: Gross rent is the monthly rent plus the estimated average monthly cost of utilities (electricity, gas, water and sewer) and fuels (oil, coal, kerosene, wood, etc.). This shows the number of renter-occupied units paying cash rent (excluding one-family houses on ten or more acres) and percentage which paid between $1,000 to $1,499 per month.	0	0%
$1,500 to $1,999: Gross rent is the monthly rent plus the estimated average monthly cost of utilities (electricity, gas, water and sewer) and fuels (oil, coal, kerosene, wood, etc.). This shows the number of renter-occupied units paying cash rent (excluding one-family houses on ten or more acres) and percentage which paid between $1,500 to $1,999 per month.	0	0%
$2,000 to $2,499: Gross rent is the monthly rent plus the estimated average monthly cost of utilities (electricity, gas, water and sewer) and fuels (oil, coal, kerosene, wood, etc.). This shows the number of renter-occupied units paying cash rent (excluding one-family houses on ten or more acres) and percentage which paid between $2,000 to $2,499 per month.	0	0%
$2,500 to $2,999: Gross rent is the monthly rent plus the estimated average monthly cost of utilities (electricity, gas, water and sewer) and fuels (oil, coal, kerosene, wood, etc.). This shows the number of renter-occupied units paying cash rent (excluding one-family houses on ten or more acres) and percentage which paid between $2,500 to $2,999 per month.	0	0%
$3,000 or more: Gross rent is the monthly rent plus the estimated average monthly cost of utilities (electricity, gas, water and sewer) and fuels (oil, coal, kerosene, wood, etc.). This shows the number of renter-occupied units paying cash rent (excluding one-family houses on ten or more acres) and percentage which paid $3,000 or more per month.	0	0%
No Rent: Gross rent is the monthly rent plus the estimated average monthly cost of utilities (electricity, gas, water and sewer) and fuels (oil, coal, kerosene, wood, etc.). This shows the number of renter-occupied units paying cash rent (excluding one-family houses on ten or more acres) and percentage which pay no rent per month.	0	0%

All ZIP Codes assigned this City name by the USPS.

Pie Chart showing Gross Rent Paid by renters for all ZIPs in Duncans Mills, CA. A table also provides the same information. Load Chart

Source: U.S. Census 2019-2023 American Community Survey 5-Year Estimates. Table Table DP04. SELECTED HOUSING CHARACTERISTICS

Pie Chart & Table (ZIPs)Comparison Chart

Health Insurance

Private Insurance: Census Estimate of the Civilian non-institutionalized people with private health insurance for all ZIPs. Private health insurance is a plan provided through an employer or union; a plan purchased by an individual from an insurance company; or TRICARE or other military health coverage.	0	0%
Public Insurance: Census Estimate of the Civilian non-institutionalized people with public health insurance for all ZIPs. Public coverage includes the federal programs Medicare, Medicaid and other medical assistance programs, VA and CHAMPVA Health Care; the Children?s Health Insurance Program (CHIP); and individual state health plans. The ACS questionnaire does not specifically ask about these types of coverage, but respondents who indicate these types of coverage are counted as having public coverage.	0	0%
No Insurance: Census Estimate of the Civilian non-institutionalized people with no health insurance of any kind for all ZIPs. People whose only health coverage is Indian Health Service are uninsured as IHS is not considered comprehensive coverage.	0	0%

All ZIP Codes assigned this City name by the USPS.

Pie Chart showing Civilian non-institutionalized people with Private [0, 0%], Public [0, 0%], or No Health Insurance [0, 0%]coverage of individuals for all ZIPs in Duncans Mills, CA. A table also provides the same data. Load Chart

Source: U.S. Census 2017-2021 American Community Survey 5-Year Estimates. Table DP03. SELECTED ECONOMIC CHARACTERISTICS

Other Duncans Mills Demographics

# Residential Mailboxes: The number of active residential delivery mailboxes and centralized units. This excludes PO Boxes and all other contract box types.	0
# Business Mailboxes: The number of active business delivery mailboxes and centralized units. This excludes PO Boxes and all other contract box types.	0
Total Delivery Receptacles: The total number of delivery receptacles. This includes curb side mailboxes, centralized units, PO Boxes, NDCBU, and contract boxes. This count is for Residential and Business combined.	158
Single Family Delivery Units: Total count of single family mail delivery receptacles; generally analogous to homes.	0
Multi Family Delivery Units: Total count of multifamily mail delivery receptacles; generally analogous to apartments.	0

# of Businesses: The total number of Business Establishments. Data taken from Business Census 2023.	18
1st Quarter Payroll: The total payroll for the first quarter. Data taken from Business Census 2023.	$799,000
Annual Payroll: The total annual payroll . Data taken from Business Census 2023.	$3,360,000
# of Employees: The total number of employees for all ZIP Codes in this City. Data taken from Business Census 2023.	86

All ZIP Codes assigned this City name by the USPS.

Cities near Duncans Mills, CA

Monte Rio, CA (~2.86 miles)
Occidental, CA (~3.93 miles)
Guerneville, CA (~5.95 miles)
Jenner, CA (~6.60 miles)
Bodega Bay, CA (~7.08 miles)
Forestville, CA (~9.54 miles)
Bodega, CA (~10.21 miles)
Sebastopol, CA (~10.98 miles)
Graton, CA (~11.22 miles)
Valley Ford, CA (~11.86 miles)
Windsor, CA (~15.47 miles)
Santa Rosa, CA (~15.55 miles)
Cazadero, CA (~16.04 miles)
Fulton, CA (~16.08 miles)
Healdsburg, CA (~16.74 miles)
Marshall, CA (~19.85 miles)
Rohnert Park, CA (~21.24 miles)
Cotati, CA (~21.45 miles)
Petaluma, CA (~22.20 miles)
Cloverdale, CA (~22.96 miles)

References

U.S. Postal Service [Last Updated: 7/1/2025], https://www.usps.com
ZIP-Codes.com Internal Data Creation [Last Updated: 7/1/2025], https://www.zip-codes.com
U.S. Geological Survey [Updated as needed], https://www.usgs.gov
U.S. Census [Updated Yearly], https://www.census.gov
U.S. Census 2020 [Decennial] [Last Updated: 5/25/2023], https://www.census.gov