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Multi-Family Dwellings (Generic, Any Combination)Residential
Last sold for $950,000 on Oct 11, 2005

20 LOWER ALCATRAZ PL

MILL VALLEY, CA 94941
0
Baths
3,036 ft²
Living AreaTotal finished area of the structures, from county records. Some counties include shared space like hallways or a building gym, so it may not match a listing.
3,851 ft²
Lot SizeThe size of the land the home sits on, from county records.
1920
Year BuiltThe year the home was originally built, according to county records.

Valuation

Last SaleThe most recent sale price and date from the recorded deed. Transfers between family members or companies may not reflect market value.$950,000 · Oct 11, 2005

Tax & Assessment

Property TaxThe property tax billed for this tax year. It usually pays for schools, roads, and local services.$20,312 (2025)
Assessed ValueThe value the county assigns to this home to calculate property tax. It is often lower than what the home would sell for.$1,361,262 (2026)
Assessed LandThe share of the county's assessed value that comes from the land itself, not the buildings.$975,646
Assessed ImprovementsThe share of the county's assessed value that comes from the buildings and other structures on the land.$385,616
Previous AssessedThe county's assessed value from the year before, useful for seeing how the assessment changed.$1,334,580

Property Facts

Property TypeThe broad category the county puts this property in, such as residential or commercial.Multi-Family Dwellings (Generic, Any Combination)
CountyMARIN
Effective Year BuiltAn adjusted build year that accounts for condition and major remodels. A big renovation can make a home count as newer than it is.1982
Lot (acres)The size of the land the home sits on, from county records.0.09
PoolWhether the property has a pool, and what kind, such as in-ground.No

Transaction History(8)

Sales and refinances filed with the county for this home. Not every transfer is a normal sale, so check the type before comparing prices.

Assigned SchoolsThe public schools this address is zoned for. Boundaries change, so confirm with the district before you count on it.

E
Old Mill Elementary SchoolA+
Elementary · Grades KG–5 · 0.3 mi
M
Mill Valley Middle SchoolA
Middle · Grades 6–8 · 1.4 mi
H
Tamalpais High SchoolA+
High · Grades 9–12 · 1.6 mi

District: Mill Valley Elementary School District

Neighborhood · ZIP 94941These are comparison scores, not percentages. 100 equals the national average, so 150 means about 50% above average.

CrimeLocal crime compared with the rest of the country, where 100 is average. It reflects things like population density, income, and how crime gets reported.91
Air pollutionOverall air pollution compared with the rest of the country, where 100 is average. Lower is cleaner.84
EarthquakeEarthquake risk and likely building damage compared with the rest of the country, where 100 is average. Scores can run far above 100.439

Index scale: 100 = US average (tick). Lower is better.

Homes occupiedThe share of homes here that someone lives in. The rest sit empty, including vacation and for-sale homes.93%
Bachelor's or higherThe share of adults 25 and older whose highest degree is a bachelor's degree.37%
Poverty rateThe share of people whose household income falls below the federal poverty line, which varies by family size.5.3%
UnemploymentThe share of men 16 and older who are out of work and actively looking. Only men are counted in this figure.1.1%
PopulationHow many people live in this area.30,767
DensityPeople per square mile. Higher numbers mean a more crowded, urban area.1,462 / mi²
Median incomeThe middle household income here — half of households earn more, half earn less.$194,124
Average incomeThe average household income. It runs higher than the median when a few high earners pull it up.$248,795
Average tempThe average temperature here across a full year.57°F
Annual precipHow much rain and melted snow falls here in a typical year.42 in
SunshineThe share of daylight hours that get direct sun in a typical year, counting cloud cover.78%

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Data by ATTOM. Valuations are automated estimates, not appraisals. Photos from Google Street View and may not depict the current property state.

How this home compares

20 Lower Alcatraz Pl measured against every home in its neighborhood, its ZIP code and its county, using county assessor records refreshed nightly. A home can stand out in one of those areas and look ordinary in another, because each one holds a different mix of homes.

  • Bigger than 87% of homes in Marin County
  • Has a smaller lot than 97% of homes in Blithedale Canyon
  • Older than 93% of homes in Marin County

How it measures up in Mill Valley 94941

The dot is this home. The mark in the middle is the typical home in Mill Valley 94941.

Living area3,036 ft²
SmallerTypical 1,968 ft²Bigger

Bigger than 85% of homes nearby

Lot size3,851 ft²
SmallerTypical 0.19 acBigger

Bigger than 12% of homes nearby

Year built1920
OlderTypical 1959Newer

Newer than 9% of homes nearby

How 20 Lower Alcatraz Pl ranks against every home in each area.
MeasureThis homeBlithedale CanyonMill Valley 94941Marin County
Living areabigger than3,036 ft²76% of homes85% of homes87% of homes
Lot sizebigger than3,851 ft²3% of homes12% of homes17% of homes
Year builtnewer than192023% of homes9% of homes7% of homes

About 20 Lower Alcatraz Pl

When did 20 Lower Alcatraz Pl, Mill Valley, CA last sell?

20 Lower Alcatraz Pl, Mill Valley, CA last sold on Oct 11, 2005 for $950,000, according to the county's recorded deed.

How big is 20 Lower Alcatraz Pl, Mill Valley, CA?

20 Lower Alcatraz Pl, Mill Valley, CA has 3,036 square feet of living space and a 0.09-acre lot.

When was 20 Lower Alcatraz Pl, Mill Valley, CA built?

20 Lower Alcatraz Pl, Mill Valley, CA was built in 1920, making it 106 years old.

What schools serve 20 Lower Alcatraz Pl, Mill Valley, CA?

20 Lower Alcatraz Pl, Mill Valley, CA is assigned to Old Mill Elementary School (elementary), rated A+; Mill Valley Middle School (middle), rated A; Tamalpais High School (high), rated A+. All sit in Mill Valley Elementary School District. Attendance boundaries change — confirm with the district before relying on an assignment.

How does 20 Lower Alcatraz Pl, Mill Valley, CA compare to other homes in Mill Valley 94941?

Among the 10,554 homes in Mill Valley 94941, it is bigger than 85% of them (3,036 ft² against a typical 1,968 ft²), its lot is bigger than 12% of them (3,851 ft² against a typical 0.19 ac) and it is newer than 9% of them (1920 against a typical 1959). These shares are recounted nightly from the full county assessor record for each area, not from active listings.

What are the property taxes on 20 Lower Alcatraz Pl, Mill Valley, CA?

The 2025 property tax bill for 20 Lower Alcatraz Pl, Mill Valley, CA was $20,312. The county assessed it at $1,361,262.

More homes on Lower Alcatraz Pl

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Assigned schools

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