| City: | San Luis Obispo, California |
| City Alias: | Sn Luis Obisp |
| Names to Avoid: | California Mens Colony Slo |
| County: | San Luis Obispo County |
| Timezone: | Pacific (GMT -08:00) |
| Local Time: | 10:39:50 PM |
| Population: | 3,806 [See All] |
| Area Codes: | 805 / 820 |
| Classification: | Unique [Company/Government] |
| Coordinates: | 35.2839, -120.6701 |
| Land Area: | 0.4 sq mi |
| Quick Link: |
California Men's Colony, a state prison operated by the California Department of Corrections and Rehabilitation, operates under dedicated ZIP code 93409 in San Luis Obispo County. Opened in July 1954 in temporary quarters at the former Camp San Luis Obispo military hospital, CMC originally served as an experiment in penology designed to house older, infirm, and disabled male inmates aged over 40. The facility has occupied this unique postal designation for over two decades.
The prison encompasses 356 acres with two separate facilities: West Facility opened in 1954 and East Facility in 1961. The West Facility was remodeled by 50 inmates from Folsom Prison specifically selected for their skills in carpentry, plumbing, and construction trades. The location offers a scenic setting along the central California coast, approximately halfway between Los Angeles and San Francisco.
The 2020 Census counted 3,806 residents within this ZIP, with 100% living in institutional group quarters. The median age of 45.0 years reflects the older inmate population that was the facility's original mission. Zero housing units exist in this ZIP, as all residents are incarcerated individuals. The entirely institutional character distinguishes this from residential ZIP codes.
CMC has housed several notable inmates over its history, including psychologist Timothy Leary (who escaped in 1970 with help from the Weatherman organization), Black Panther founder Huey P. Newton, and Manson Family associate Bobby Beausoleil. The West facility is currently slated for closure. San Luis Obispo is the valid mailing city for this designation.
| Population: | 3,806 |
| Median Age: | 45.0 |
| Housing Units: | 0 |
Buildings registered in the USPS ZIP+4 database with designated codes for direct mail delivery.
ZIP Code 93409 has 3,806 residents and 0 households. The median age is 45.0 years, significantly older than the state (37.5) and older than the nation (38.8). The gender split is 99.8% male and 0.2% female, which is much higher than the national male share (49.1%), making this a male-majority area. Largest groups are Black or African American (44.3%, much higher than the state average of 5.7% and well above the national average of 12.4%) and Other / Two or More Races (31.8%, much higher than the state average of 21.2% and well above the national average of 8.4%); Hispanic or Latino residents make up 31.8%, which is much higher than the national average (18.7%), and Black or African American share is much higher than both the state (5.7%) and national averages (12.4%) and Other / Two or More Races share is much higher than both the state (21.2%) and national averages (8.4%).
Explore More:Population Over TimeBy Age & GenderBy RaceBy GenderNativity & Citizenship
| 2020 Population: | 3,806Source: Census DHC |
| 2024 ACS Population Estimate: | 2,687Source: Census ACS |
| 2026 ZC Population Estimate: | 0Source: ZIP-Codes.com |
| Population Density: | 9,515.0 people per sq mile |
| Average Income: | $0Source: Census ACS |
| Households: | 0Source: Census DHC |
| Average House Value: | $0Source: Census ACS |
| Persons Per Household: | 0.00Source: Census DHC |
| Average Family Size: | 0.00Source: Census ACS |
| Group | 2010 | 2011 | 2102 | 2013 | 2014 | 2015 | 2016 | 2017 | 2018 | 2019 | 2020 | 2021 | 2022 | 2023 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Census ACS Population Estimate | -- | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 2,989 | 2,591 | 2,687 |
| Decennial Census | 0 | -- | -- | -- | -- | -- | -- | -- | -- | -- | 3,806 | -- | -- | -- |
Median Age: 45
Male Median Age: 45
Female Median Age: 67.5
| Group | < 5 | 5-9 | 10-14 | 15-19 | 20-24 | 25-29 | 30-34 | 35-39 | 40-44 | 45-49 | 50-54 | 55-59 | 60-64 | 65-69 | 70-74 | 75-79 | 80-84 | 85+ |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Male | 0 | 0 | 0 | 6 | 175 | 390 | 478 | 427 | 421 | 454 | 399 | 379 | 289 | 255 | 82 | 27 | 11 | 5 |
| Female | 0 | 0 | 0 | 1 | 0 | 0 | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 3 | 0 | 1 | 1 | 1 |
| Total | 0 | 0 | 0 | 7 | 175 | 390 | 479 | 427 | 421 | 454 | 399 | 379 | 289 | 258 | 82 | 28 | 12 | 6 |
| White: | 763 | 15.39% |
| Black: | 1,687 | 34.03% |
| Hispanic:* | 1,209 | 24.39% |
| Asian: | 41 | 0.83% |
| American Indian: | 32 | 0.65% |
| Hawaiian: | 15 | 0.30% |
| Other: | 1,210 | 24.41% |
| Total: | 4,957 | 100% |
| Gender | Count | % | Median Age |
|---|---|---|---|
| Males: | 3,798 | 99.79% | 45.0 years |
| Females: | 8 | 0.21% | 67.5 years |
| Total: | 3,806 | 100% | 45.0 years |
| Native, born in the United States: | 2,272 | 84.56% |
| Native, born in PR, Island Areas, or abroad: | 36 | 1.34% |
| Foreign born, naturalized U.S. citizen: | 125 | 4.65% |
| Foreign born, not a U.S. citizen: | 254 | 14.10% |
| Total Population: | 2,687 | 100% |
| Total Native Population: | 2,308 | 85.90% |
| Total Foreign-born Population: | 379 | 14.10% |
In 2023, the Median household income is $0, which is far less than the state median ($96,334), and above its 2019 pre-pandemic level by $0. Family households earn a median of $0 versus $0 for nonfamily households (a difference of $0). By gender, male median income is $25,573 and female is $0, which is well under the state female median ($61,569), with a current gap of $25,573 that has widened from 2011 to 2023. The labor-force participation rate is 0.0%, which is much lower than the state rate (63.9%).
Explore More:Income Over TimeHousehold IncomeEmployment StatusBy Occupation
| Income Type | 2011 | 2012 | 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 | $24,107 | $25,573 |
| Median Female Income | $0 | $0 | $0 | $0 | $0 | $0 | $0 | $0 | $0 | $0 | $0 | $0 | $0 |
| Employed: | 0 | 0.00% |
| Unemployed: | 0 | 0.00% |
| Not In Labor Force: | 2,687 | 100.00% |
| Total: | 2,687 | 100% |
| Management, business, science, and arts: | 0 | 0% |
| Service: | 0 | 0% |
| Sales and Office: | 0 | 0% |
| Natural resources, construction, and maintenance: | 0 | 0% |
| Production, transportation, and material moving: | 0 | 0% |
| Total Civilian Employed Population: | 0 | 100% |
In 2023, 1.90% of adults (25+) have a bachelor's degree or higher, which is markedly below the state rate (36.50%). High school or higher is 57.60%, which is far lower than the national rate (89.40%). Insufficient data for health insurance coverage. Insufficient data for poverty. Among residents ages 3+, the largest enrollment group is high school (54.77%). College enrollment is 44.06%, which is far higher than the national rate (26.70%), indicating the community is likely a college hub with student-driven housing and services.
Explore More:Educational AttainmentHealth InsurancePoverty Over TimeSchool Enrollment
| Less than 9th grade: | 175 | 6.85% |
| 9th to 12th grade, no diploma: | 908 | 35.52% |
| High school graduate (includes equivalency): | 580 | 22.69% |
| Some college, no degree: | 755 | 29.54% |
| Associate's degree: | 90 | 3.52% |
| Bachelor's degree: | 25 | 0.98% |
| Graduate or professional degree: | 23 | 0.90% |
| Total: | 2,556 | 100% |
| High school or higher: | 1,473 | 57.63% |
| Bachelor's degree or higher: | 48 | 1.88% |
| Private Insurance: | 0 | 0% |
| Public Insurance: | 0 | 0% |
| No Insurance: | 0 | 0% |
| Total: | 0 | 100% |
| Has Health Insurance: | 0 | 0% |
| Group | 2011 | 2102 | 2013 | 2014 | 2015 | 2016 | 2017 | 2018 | 2019 | 2020 | 2021 | 2022 | 2023 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| % of People in Poverty | 0.0% | 0.0% | 0.0% | 0.0% | 0.0% | 0.0% | 0.0% | 0.0% | 0.0% | 0.0% | 0.0% | 0.0% | 0.0% |
Note: Counts of Families & People in poverty are not published at the ZIP Code level due to small sample sizes. Percentages shown are survey estimates from the American Community Survey (ACS). They may differ from official poverty statistics. The U.S. Census Bureau defines poverty status by comparing a family's or individual's total income with federal poverty thresholds that vary by family size and composition.
| Nursery School, Preschool: | 0 | 0.00% |
| Kindergarten: | 0 | 0.00% |
| Elementary school (grades 1-8): | 13 | 1.17% |
| High school (grades 9-12): | 609 | 54.77% |
| College or graduate school: | 490 | 44.06% |
| Total: | 1,112 | 100% |
| Early Childhood: | 0 | 0.00% |
| K-12 (Primary & Secondary School): | 622 | 55.94% |
ZIP Code 93409 is assigned to a single organization or institution. Detailed business demographics are not published for unique ZIP Codes.
| # Residential Mailboxes: | 0Source: USPS |
| # Business Mailboxes: | 0Source: USPS |
| Total Delivery Receptacles: | 0Source: USPS |
| Single Family Delivery Units: | 0Source: USPS |
| Multi Family Delivery Units: | 0Source: USPS |
| # of Businesses: | 0Source: CBP |
| 1st Quarter Payroll: | $0Source: CBP |
| Annual Payroll: | $0Source: CBP |
| # of Employees: | 0Source: CBP |
ZIP Code 93409 is located in San Luis Obispo County, California, within the San Luis Obispo-Paso Robles, CA Metropolitan Statistical Area (CBSA 42020) and California's 24th Congressional District. This Metro area has a population of 281,486 people, about 1.35% of whom live in ZIP Code 93409. It covers 0.4 sq mi of land and a water area of 0 sq mi.
| CBSA Name: | San Luis Obispo-Paso Robles, CASource: Census |
| CBSA Number: | 42020Source: Census |
| CBSA Type: | MetroSource: Census |
| CBSA Division: | --Source: Census |
| CBSA Population: | 281,486Source: Census |
| MSA: | San Luis Obispo-Atascadero-Paso Robles, CA MSASource: Census |
| Land Area: | 0.4 sq miSource: Census |
| Water Area: | --Source: Census |
| Congressional District: | 24Source: USPS |
| Congressional Land Area: | 6883.35 sq miSource: Census |
| PMSA: | --Source: Census |
| Intro Date: | < 2004-10Source: ZIP-Codes.com |
| Place FIPS Code: | 0668154Source: Census |
| Place Name: | San Luis Obispo city; CaliforniaSource: Census |
We could not locate which school district 93409 belongs to, but we will update this once new district data is released. There are no public schools nor private schools with a mailing address in this ZIP Code. Listing Nearby schools instead. It also has 6 colleges, universities or post secondary education institutions nearby which would be a short commute to.
Our sources include trusted federal and licensed data from the United States Postal Service, U.S. Census Bureau, U.S. Geological Survey, Centers for Medicare & Medicaid Services, and the National Center for Education Statistics, along with proprietary datasets created by ZIP-Codes.com. Data last updated on January 1, 2026.