{{distinguish|Alta, California}} {{Use American English|date=July 2025}} {{Use mdy dates|date=April 2024}} {{Infobox settlement <!--See the Table at Infobox Settlement for all fields and descriptions of usage--> <!-- Basic info ----------------> |name = Alto |other_name = |native_name = |nickname = |settlement_type = [[Census-designated place]] |image_skyline = |imagesize = |image_caption = |pushpin_map = California |pushpin_label_position = bottom |pushpin_mapsize = |pushpin_map_caption = Location in California <!-- Location ------------------> |subdivision_type = Country |subdivision_name = {{USA}} |subdivision_type1 = [[U.S. state|State]] |subdivision_name1 = {{flag|California}} |subdivision_type2 = [[List of counties in California|County]] |subdivision_name2 = [[Marin County, California|Marin]] |subdivision_type3 = Metro |subdivision_name3 = [[San Francisco Bay Area]] <!-- Population ------------------> |population_as_of = [[2020 United States Census|2020]] |population_footnotes = |population_total = 732 | population_density_km2 = 2247.56 <!-- Area------------------> |area_magnitude = | unit_pref = Imperial | area_footnotes = <ref name="CenPopGazetteer2020">{{Cite web |title=2020 U.S. Gazetteer Files |url=https://www2.census.gov/geo/docs/maps-data/data/gazetteer/2020_Gazetteer/2020_gaz_place_06.txt |access-date=October 30, 2021 |publisher=United States Census Bureau}}</ref> | area_total_sq_mi = 0.13 | area_land_sq_mi = 0.13 | area_water_sq_mi = 0.00 | area_total_km2 = 0.33 | area_land_km2 = 0.33 | area_water_km2 = 0.00 | area_water_percent = 0 | area_note =
<!-- General information --> |timezone = [[Pacific Time Zone|Pacific (PST)]] |utc_offset = -8 |timezone_DST = PDT |utc_offset_DST = -7
|<!-- Politics -----------------> |established_title = <!-- Settled --> |established_date = |coordinates = {{coord|37|54|16|N|122|31|32|W|region:US-CA|display=inline,title}} |elevation_footnotes = <ref name="gnis">{{gnis|218191}}</ref> |elevation_m = 8 |elevation_ft = 26 <!-- Area/postal codes & others --> |postal_code_type = [[ZIP Code]] |postal_code = |area_code = |blank_name = [[Geographic Names Information System|GNIS]] feature ID |blank_info = 218191; 2582933 |website = |footnotes = {{gnis|218191}}; {{gnis|2582933}}
|pop_est_as_of = |pop_est_footnotes = |population_est = |image_map = File:Marin County California Incorporated and Unincorporated areas Alto Highlighted 0601416.svg |map_caption = Location of Alto in Marin County, California. |population_density_sq_mi = 5809.52 }} '''Alto''' ([[Spanish language|Spanish]] for "Tall") is a [[census-designated place]]<ref>{{gnis|2582933}}</ref> adjacent to [[Mill Valley, California]], United States, located in [[Marin County, California|Marin County]].<ref name="gnis" /> It lies at an elevation of 26 feet (8 m).<ref name="gnis" /> The population was 732 at the 2020 census.
==Geography== According to the [[United States Census Bureau]], the CDP covered an area of {{convert|0.326|km2|mi2|3|sp=us}}, all land.
==Demographics== {{US Census population |2010= 711 |2020= 732 |estyear= |estimate= |estref= |align-fn=center |footnote=U.S. Decennial Census<ref name="DecennialCensus">{{cite web|url=https://www.census.gov/programs-surveys/decennial-census/decade.html|title=Decennial Census by Decade|website=[[United States Census Bureau]]|access-date=}}</ref><br> 1860–1870<ref name=1870CensusCA1>{{Cite web|title= 1870 Census of Population - Population of Civil Divisions less than Counties - California - Almeda County to Sutter County |url=https://www2.census.gov/library/publications/decennial/1870/population/1870a-12.pdf|website=[[United States Census Bureau]]|via= [[Wayback Machine]] |archive-url=https://web.archive.org/web/20250126025002/https://www2.census.gov/library/publications/decennial/1870/population/1870a-12.pdf| archive-date=January 26, 2025}}</ref><ref name=1870CensusCA2>{{Cite web|title= 1870 Census of Population - Population of Civil Divisions less than Counties - California - Tehama County to Yuba County |url=https://www2.census.gov/library/publications/decennial/1870/population/1870a-13.pdf|website=[[United States Census Bureau]]|via= [[Wayback Machine]] |archive-url=https://web.archive.org/web/20250202095153/https://www2.census.gov/library/publications/decennial/1870/population/1870a-13.pdf| archive-date=February 2, 2025}}</ref> 1880-1890<ref name=1890CensusCA>{{Cite web|title= 1890 Census of Population - Population of California by Minor Civil Divisions |url=https://www2.census.gov/library/publications/decennial/1890/bulletins/demographics/134-population-of-ca.pdf|website=[[United States Census Bureau]]|via= [[Wayback Machine]] |archive-url=https://web.archive.org/web/20250311213742/https://www2.census.gov/library/publications/decennial/1890/bulletins/demographics/134-population-of-ca.pdf| archive-date=March 11, 2025}}</ref><br> 1900<ref name=1900CensusCA>{{Cite web|title= 1900 Census of Population - Population of California by Counties and Minor Civil Divisions |url=https://www2.census.gov/library/publications/decennial/1900/bulletins/demographic/10-population-ca.pdf|website=[[United States Census Bureau]]|via= [[Wayback Machine]] |archive-url=https://web.archive.org/web/20250304013034/https://www2.census.gov/library/publications/decennial/1900/bulletins/demographic/10-population-ca.pdf| archive-date=March 4, 2025}}</ref> 1910<ref name=1910CensusCA>{{Cite web|title=1910 Census of Population - Supplement for California|url=https://www2.census.gov/library/publications/decennial/1910/abstract/supplement-ca.pdf|website=[[United States Census Bureau]]|access-date=February 4, 2025|via= [[Wayback Machine]] |archive-url=https://web.archive.org/web/20250404180724/https://web.archive.org/web/20240823050629/https://www2.census.gov/library/publications/decennial/1910/abstract/supplement-ca.pdf| archive-date= April 4, 2025}}</ref> 1920<ref name=1920CensusCA>{{Cite web|title= 1920 Census of Population - Number of Inhabitants - California |url=https://www2.census.gov/library/publications/decennial/1920/bulletins/demographics/population-ca-number-of-inhabitants.pdf|website=[[United States Census Bureau]] |via= [[Wayback Machine]] |archive-url=https://web.archive.org/web/20250428023259/https://www2.census.gov/library/publications/decennial/1920/bulletins/demographics/population-ca-number-of-inhabitants.pdf| archive-date=April 28, 2025}}</ref><br> 1930<ref name=1930CensusCA>{{Cite web|title= 1930 Census of Population - Number and Distribution of Inhabitants - California |url=https://www2.census.gov/library/publications/decennial/1930/population-volume-1/03815512v1ch03.pdf|website=[[United States Census Bureau]] |via= [[Wayback Machine]] |archive-url=https://web.archive.org/web/20250317202706/https://www2.census.gov/library/publications/decennial/1930/population-volume-1/03815512v1ch03.pdf| archive-date= March 17, 2025}}</ref> 1940<ref name=1940CensusCA>{{Cite web|title= 1940 Census of Population - Number of Inhabitants - California |url=https://www2.census.gov/library/publications/decennial/1940/population-volume-1/33973538v1ch03.pdf|website=[[United States Census Bureau]] |via= [[Wayback Machine]] |archive-url=https://web.archive.org/web/20250126024959/https://www2.census.gov/library/publications/decennial/1940/population-volume-1/33973538v1ch03.pdf | archive-date=January 26, 2025}}</ref> 1950<ref name=1950CensusCA>{{Cite web|title= 1950 Census of Population - Number of Inhabitants - California |url=https://www2.census.gov/library/publications/decennial/1950/population-volume-1/vol-01-08.pdf|website=[[United States Census Bureau]] |via= [[Wayback Machine]] |archive-url=https://web.archive.org/web/20250219112141/https://www2.census.gov/library/publications/decennial/1950/population-volume-1/vol-01-08.pdf | archive-date=February 19, 2025}}</ref><br> 1960<ref name=1960CensusCA>{{Cite web|title= 1960 Census of Population - Number of Inhabitants - California |url=https://www2.census.gov/library/publications/decennial/1960/population-volume-1/vol-01-06-c.pdf|website=[[United States Census Bureau]] |via= [[Wayback Machine]] |archive-url=https://web.archive.org/web/20250322000358/https://www2.census.gov/library/publications/decennial/1960/population-volume-1/vol-01-06-c.pdf| archive-date=March 22, 2025}}</ref><ref name=1960CensusCA1>{{Cite web|title= 1960 Census of Population - General population Characteristics - California |url=https://www2.census.gov/library/publications/decennial/1960/population-volume-1/vol-01-06-d.pdf|website=[[United States Census Bureau]] |via= [[Wayback Machine]] |archive-url=https://web.archive.org/web/20250322000356/https://www2.census.gov/library/publications/decennial/1960/population-volume-1/vol-01-06-d.pdf | archive-date=March 22, 2025}}</ref> 1970<ref name=1970CensusCA>{{Cite web|title= 1970 Census of Population - Number of Inhabitants - California |url=https://www2.census.gov/prod2/decennial/documents/1970a_ca1-01.pdf|website=[[United States Census Bureau]] |via= [[Wayback Machine]] |archive-url=https://web.archive.org/web/20250226084958/https://www2.census.gov/prod2/decennial/documents/1970a_ca1-01.pdf | archive-date=February 26, 2025}}</ref> 1980<ref name=1980CensusCA>{{Cite web|title= 1980 Census of Population - Number of Inhabitants - California |url=https://www2.census.gov/prod2/decennial/documents/1980a_caAB-01.pdf|website=[[United States Census Bureau]] |via= [[Wayback Machine]] |archive-url=https://web.archive.org/web/20250126024959/https://www2.census.gov/prod2/decennial/documents/1980a_caAB-01.pdf | archive-date=January 26, 2025}}</ref><br> 1990<ref name=1990CensusCA>{{Cite web|title= 1990 Census of Population - Population and Housing Unit Counts - California |url=https://www2.census.gov/prod2/cen1990/cph2/cph-2-6.pdf|website=[[United States Census Bureau]] |via= [[Wayback Machine]] |archive-url=https://web.archive.org/web/20250126025005/https://www2.census.gov/prod2/cen1990/cph2/cph-2-6.pdf| archive-date=January 26, 2025}}</ref> 2000<ref name=2000CensusCA>{{Cite web|title= 2000 Census of Population - Population and Housing Unit Counts - California |url=https://www2.census.gov/library/publications/2003/dec/phc-3-6.pdf|website=[[United States Census Bureau]] |via= [[Wayback Machine]] |archive-url=https://web.archive.org/web/20250322000357/https://www2.census.gov/library/publications/2003/dec/phc-3-6.pdf| archive-date=March 22, 2025}}</ref> 2010<ref name=2010CensusCA>{{Cite web|title= 2010 Census of Population - Population and Housing Unit Counts - California |url=https://www2.census.gov/library/publications/decennial/2010/cph-2/cph-2-6.pdf|website=[[United States Census Bureau]] |via= [[Wayback Machine]] |archive-url=https://web.archive.org/web/20250328034325/https://www2.census.gov/library/publications/decennial/2010/cph-2/cph-2-6.pdf| archive-date=March 28, 2025}}</ref><br> 2020 | align = right }}
Alto first appeared as a [[census-designated place]] in the [[2010 United States census]].<ref name=2010CensusCA/>
===Racial and ethnic composition===
{| class="wikitable sortable" style="text-align:center;" |+'''Alto CDP, California – Racial and ethnic composition'''<br><small>{{nobold|''Note: the US Census treats Hispanic/Latino as an ethnic category. This table excludes Latinos from the racial categories and assigns them to a separate category. Hispanics/Latinos may be of any race.''}}</small> !Race / Ethnicity <small>(''NH = Non-Hispanic'')</small> !Pop 2010<ref name=2010CensusP2>{{Cite web|title=P2: Hispanic or Latino, and Not Hispanic or Latino by Race – 2010: DEC Redistricting Data (PL 94-171) – Alto CDP, California|url=https://data.census.gov/cedsci/table?q=p2&g=160XX00US0601416&tid=DECENNIALPL2010.P2|website=[[United States Census Bureau]] |access-date= }}</ref> !style="background-color: #ffffb3;" |Pop 2020<ref name=2020CensusP2>{{Cite web|title=P2: Hispanic or Latino, and Not Hispanic or Latino by Race – 2020: DEC Redistricting Data (PL 94-171) – Alto CDP, California|url=https://data.census.gov/cedsci/table?q=p2&g=160XX00US0601416&tid=DECENNIALPL2020.P2|website=[[United States Census Bureau]] |access-date= }}</ref> !% 2010 !style="background-color: #ffffb3;" |% 2020 |- |[[Non-Hispanic or Latino whites|White]] alone (NH) |585 |style='background: #ffffe6; |571 |82.28% |style='background: #ffffe6; |78.01% |- |[[Non-Hispanic or Latino African Americans|Black or African American]] alone (NH) |6 |style='background: #ffffe6; |2 |0.84% |style='background: #ffffe6; |0.27% |- |[[Native Americans in the United States|Native American]] or [[Alaska Native]] alone (NH) |1 |style='background: #ffffe6; |0 |0.14% |style='background: #ffffe6; |0.00% |- |[[Asian Americans|Asian]] alone (NH) |29 |style='background: #ffffe6; |31 |4.08% |style='background: #ffffe6; |4.23% |- |[[Native Hawaiian]] or [[Pacific Islander Americans|Pacific Islander]] alone (NH) |1 |style='background: #ffffe6; |1 |0.14% |style='background: #ffffe6; |0.14% |- |[[Race and ethnicity in the United States census|Other race]] alone (NH) |5 |style='background: #ffffe6; |13 |0.70% |style='background: #ffffe6; |1.78% |- |[[Multiracial Americans|Mixed race or Multiracial]] (NH) |33 |style='background: #ffffe6; |57 |4.64% |style='background: #ffffe6; |7.79% |- |[[Hispanic and Latino Americans|Hispanic or Latino]] (any race) |51 |style='background: #ffffe6; |57 |7.17% |style='background: #ffffe6; |7.79% |- |'''Total''' |'''711''' |style='background: #ffffe6; |'''732 ''' |'''100.00%''' |style='background: #ffffe6; |'''100.00%''' |}
===2020 census=== As of the [[2020 United States census|2020 census]], Alto had a population of 732. The population density was {{convert|5,809.5|PD/sqmi|PD/km2|sp=us|adj=off}}. The median age was 42.7 years. 24.5% of residents were under the age of 18, 4.9% aged 18 to 24, 23.2% aged 25 to 44, 33.3% aged 45 to 64, and 14.1% of residents were 65 years of age or older. For every 100 females there were 98.4 males, and for every 100 females age 18 and over there were 91.3 males age 18 and over.<ref name="Census2020DP">{{cite web|title=2020 Decennial Census Demographic Profile (DP1)|url=https://api.census.gov/data/2020/dec/dp?get=NAME,DP1_0021P,DP1_0024P,DP1_0025C,DP1_0049C,DP1_0045C,DP1_0069C,DP1_0073C,DP1_0125P,DP1_0126P,DP1_0129P,DP1_0133P,DP1_0137P,DP1_0138P,DP1_0139P,DP1_0141P,DP1_0142P,DP1_0143P,DP1_0145P,DP1_0146P,DP1_0147C,DP1_0148C,DP1_0149C,DP1_0156C,DP1_0157C,DP1_0158C,DP1_0159P,DP1_0160P&for=place%3A01416&in=state%3A06|website=United States Census Bureau|year=2021|access-date=April 27, 2026|df=mdy}}</ref><ref name="Census2020PL">{{cite web|title=2020 Decennial Census Redistricting Data (Public Law 94-171)|url=https://api.census.gov/data/2020/dec/pl?get=NAME,P1_001N,P1_003N,P1_004N,P1_005N,P1_006N,P1_007N,P1_008N,P1_009N,P2_001N,P2_002N,H1_001N,H1_002N&for=place%3A01416&in=state%3A06|website=United States Census Bureau|year=2021|access-date=April 27, 2026|df=mdy}}</ref>
100.0% of residents lived in urban areas, while 0.0% lived in rural areas.<ref name="Census2020DHC">{{cite web|title=2020 Decennial Census Demographic and Housing Characteristics (DHC)|url=https://api.census.gov/data/2020/dec/dhc?get=NAME,P2_002N,P2_003N&for=place%3A01416&in=state%3A06|website=United States Census Bureau|year=2023|access-date=April 27, 2026|df=mdy}}</ref>
There were 294 households, of which 34.0% had children under the age of 18 living in them. Of all households, 51.0% were married-couple households, 5.8% were [[cohabitation|cohabiting]] couple households, 15.3% were households with a male householder and no spouse or partner present, and 27.9% were households with a female householder and no spouse or partner present. About 28.9% of all households were made up of individuals and 9.6% had someone living alone who was 65 years of age or older. The average household size was 2.49. There were 193 [[family (U.S. Census)|families]] (65.6% of all households).<ref name="Census2020DP"/>
There were 314 housing units at an average density of {{convert|2,492.1|/mi2|/km2|disp=preunit|units |units|}}, of which 6.4% were vacant. The homeowner vacancy rate was 0.0% and the rental vacancy rate was 2.8%. Of occupied units, 52.7% were owner-occupied and 47.3% were occupied by renters.<ref name="Census2020DP"/> ==Education== The community is in the [[Mill Valley School District|Mill Valley Elementary School District]] and the [[Tamalpais Union High School District]].<ref>{{Cite web |title=2020 CENSUS - SCHOOL DISTRICT REFERENCE MAP: Marin County, CA |url=https://www2.census.gov/geo/maps/DC2020/PL20/st06_ca/schooldistrict_maps/c06041_marin/DC20SD_C06041.pdf |access-date=April 28, 2023 |publisher=[[U.S. Census Bureau]]}} - [https://www2.census.gov/geo/maps/DC2020/PL20/st06_ca/schooldistrict_maps/c06041_marin/DC20SD_C06041_SD2MS.txt Text list]</ref>
==References== {{reflist}}
{{Marin County, California}} {{SF Bay Area}}
{{authority control}}
[[Category:Census-designated places in Marin County, California]] [[Category:Census-designated places in California]]