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Single Family ResidenceResidential
$546,683$331 / ft²
TopHap EstimateOur estimate of what this home would sell for today, based on nearby sales, the home's size and features, and local price trends. It is a starting point, not an appraisal.· confidence 92How well the pricing models agreed with each other on this home. Higher means the estimate rests on stronger, more consistent data.· as of Sep 24, 2026
Last sold for $165,000 on Apr 29, 1994

4300 ROCK ISLAND DR

ANTIOCH, CA 94509
3
Beds
2
Baths
1,653 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.
0.17 ac
Lot SizeThe size of the land the home sits on, from county records.
1988
Year BuiltThe year the home was originally built, according to county records.
1
StoriesHow many floors the home has above ground.
9
RoomsThe total room count in county records. Counties differ on which rooms they count, so compare it loosely.
2
ParkingThe number of parking spaces on the property, including the garage.

Valuation

$547K
$503K low$590K high
Last SaleThe most recent sale price and date from the recorded deed. Transfers between family members or companies may not reflect market value.$165,000 · Apr 29, 1994

Tax & Assessment

Property TaxThe property tax billed for this tax year. It usually pays for schools, roads, and local services.$3,668 (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.$286,009 (2026)
Assessed LandThe share of the county's assessed value that comes from the land itself, not the buildings.$69,324
Assessed ImprovementsThe share of the county's assessed value that comes from the buildings and other structures on the land.$216,685
Previous AssessedThe county's assessed value from the year before, useful for seeing how the assessment changed.$280,402

Climate Risk

Overall riskThe average of the five hazard scores below, on a 0 to 100 scale. Higher means greater projected risk over the coming decades.32
1
FloodProjected flooding risk from rivers, heavy rain, and storm surge, scored 0 to 100. Higher is riskier.
64
WildfireProjected wildfire risk, scored 0 to 100, based on how much land burns in a typical year. Higher is riskier.
43
HeatProjected heat risk, scored 0 to 100, based on how many extremely hot days a year are expected. Higher is riskier.
27
StormProjected risk from heavy rainstorms, scored 0 to 100, based on how often extreme rainfall is expected. Higher is riskier.
25
DroughtProjected water shortage risk, scored 0 to 100. Higher means more strain on the local water supply.

Scores 0–100; higher = greater projected risk.

Property Facts

Property TypeThe broad category the county puts this property in, such as residential or commercial.Single Family Residence
CountyCONTRA COSTA
Lot (acres)The size of the land the home sits on, from county records.0.17
HeatingThe type of heating system in the home.Forced Air With Air Conditioning
CoolingThe type of cooling or air conditioning in the home.Central
FireplaceWhether the home has a fireplace, and what kind.Yes
GarageWhether the property has a garage, and details like whether it is attached to the home.Garage, Attached
PoolWhether the property has a pool, and what kind, such as in-ground.No

Transaction History(2)

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
John Muir Elementary SchoolD+
Elementary · Grades KG–5 · 0.4 mi
M
Dallas Ranch Middle SchoolD
Middle · Grades 6–8 · 0.8 mi
H
Deer Valley High SchoolC
High · Grades 9–12 · 1.2 mi

District: Antioch Unified School District

Neighborhood · ZIP 94509These 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.118
Air pollutionOverall air pollution compared with the rest of the country, where 100 is average. Lower is cleaner.83
EarthquakeEarthquake risk and likely building damage compared with the rest of the country, where 100 is average. Scores can run far above 100.369

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.97%
Bachelor's or higherThe share of adults 25 and older whose highest degree is a bachelor's degree.14%
Poverty rateThe share of people whose household income falls below the federal poverty line, which varies by family size.15%
UnemploymentThe share of men 16 and older who are out of work and actively looking. Only men are counted in this figure.1.4%
PopulationHow many people live in this area.67,731
DensityPeople per square mile. Higher numbers mean a more crowded, urban area.3,169 / mi²
Median incomeThe middle household income here — half of households earn more, half earn less.$76,351
Average incomeThe average household income. It runs higher than the median when a few high earners pull it up.$104,120
Average tempThe average temperature here across a full year.60°F
Annual precipHow much rain and melted snow falls here in a typical year.17 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

4300 Rock Island Dr 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.

  • Worth less than 76% of homes in Contra Costa County
  • Costs less per square foot than 82% of homes in Contra Costa County
  • Has a bigger lot than 67% of homes in Antioch 94509
  • Newer than 84% of homes in Antioch 94509

What homes are worth in Antioch 94509

Each bar is how many homes fall in that price range. The marker is this home.

This home
$150K$737K

This home is worth more than 65% of homes in Antioch 94509.

How it measures up in Antioch 94509

The dot is this home. The mark in the middle is the typical home in Antioch 94509.

Estimated value$546,683
CheaperTypical $507,244Pricier

Pricier than 65% of homes nearby

Price per ft²$331
CheaperTypical $324Pricier

Pricier than 55% of homes nearby

Living area1,653 ft²
SmallerTypical 1,496 ft²Bigger

Bigger than 62% of homes nearby

Lot size0.17 ac
SmallerTypical 0.15 acBigger

Bigger than 67% of homes nearby

Year built1988
OlderTypical 1974Newer

Newer than 84% of homes nearby

How 4300 Rock Island Dr ranks against every home in each area.
MeasureThis homeAntioch 94509Contra Costa County
Estimated valuepricier than$546,68365% of homes24% of homes
Price per ft²pricier than$33155% of homes18% of homes
Living areabigger than1,653 ft²62% of homes45% of homes
Lot sizebigger than0.17 ac67% of homes59% of homes
Year builtnewer than198884% of homes68% of homes

About 4300 Rock Island Dr

How much is 4300 Rock Island Dr, Antioch, CA worth?

The TopHap Estimate for 4300 Rock Island Dr, Antioch, CA is $546,683 as of Sep 24, 2026. The likely range is $503,017 to $590,349. The estimate is modelled from recorded sales, assessments and the property's own characteristics — it is not an appraisal.

When did 4300 Rock Island Dr, Antioch, CA last sell?

4300 Rock Island Dr, Antioch, CA last sold on Apr 29, 1994 for $165,000, according to the county's recorded deed. TopHap holds 2 recorded sales for this parcel.

How big is 4300 Rock Island Dr, Antioch, CA?

4300 Rock Island Dr, Antioch, CA has 3 bedrooms, 2 bathrooms, 1,653 square feet of living space and a 0.17-acre lot.

When was 4300 Rock Island Dr, Antioch, CA built?

4300 Rock Island Dr, Antioch, CA was built in 1988, making it 38 years old. The building has 1 story.

What schools serve 4300 Rock Island Dr, Antioch, CA?

4300 Rock Island Dr, Antioch, CA is assigned to John Muir Elementary School (elementary), rated D+; Dallas Ranch Middle School (middle), rated D; Deer Valley High School (high), rated C. All sit in Antioch Unified School District. Attendance boundaries change — confirm with the district before relying on an assignment.

How does 4300 Rock Island Dr, Antioch, CA compare to other homes in Antioch 94509?

Among the 18,216 homes in Antioch 94509, it is worth more than 65% of them ($546,683 against a typical $507,244), its price per square foot is higher than 55% of them ($331 against a typical $324), it is bigger than 62% of them (1,653 ft² against a typical 1,496 ft²), its lot is bigger than 67% of them (0.17 ac against a typical 0.15 ac) and it is newer than 84% of them (1988 against a typical 1974). Measured against all of Contra Costa County, it is worth more than 24% of homes there. These shares are recounted nightly from the full county assessor record for each area, not from active listings.

What are the property taxes on 4300 Rock Island Dr, Antioch, CA?

The 2025 property tax bill for 4300 Rock Island Dr, Antioch, CA was $3,668. The county assessed it at $286,009.

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