San Mateo County property record for 604 Alta Ave, San Mateo, CA 94403
| Property Type | Single Family Home |
|---|---|
| Details | 3 bd · 1 ba · 1,170 sqft · built 1948 |
| Lot Size | 0.115 acres (4,999 sqft) |
| Owner | Trust Name on File |
| Tax Bill | $3,187 (2025) |
| Flood Zone | Zone X (minimal risk) |
| APN | 039-111-040 |
| Primary APN | 039-111-040 |
|---|
| Bedrooms | 3 Beds |
|---|---|
| Full Baths | 1 Bath |
| Total Rooms | 6 Rooms |
| Building Area | 1,170 sqft Living Area |
| 1st Floor Area | 1,170 sqft |
| Family Room | Family Room |
| Year Built | Built 1948 |
|---|---|
| Effective Year Built | Effective 1948 |
| Lot Area | 4,999 sqft (0.115 acres) |
| Lot Dimensions | 100 ft deep x 50 ft wide |
| View / Lot | Corner |
| Garage Area | 440 sqft |
| Parking Spaces | 2 Parking Spaces |
| Cooling System | Central |
|---|---|
| Heating System | Central |
| Street Address | 604 ALTA AVE |
|---|---|
| City | SAN MATEO |
| State | CA |
| Zip | 94403-1226 |
| Property Category | Residential |
| Property Type | Residential > Single Family > Home |
| Local Zoning Code | R10006 |
| Legal Description | LOT 3 BLOCK 3 MAYWOOD RSM 24/50 |
| Legal Subdivision | MAYWOOD |
| Legal Block | 3 |
| Legal Lot Number | 3 |
| Jurisdiction | SAN MATEO CA |
| Township / Civil Division | SAN MATEO |
| Census Block Group | 2 |
| Census Block | 2012 |
| Census Tract | 606700 |
604 Alta Ave is owner-occupied and held in a trust.
Source: San Mateo County records, as of July 15, 2026
| Owner of Record | Trust Name on File |
|---|---|
| Mailing Address | 604 ALTA AVE, SAN MATEO, CA 94403-1226 |
| Occupancy | Owner Occupied |
| Owner Type | Company |
| Vesting | Trust |
Owner names and exact recorded amounts are on file and can be viewed instantly on this page with a free 10-day trial.
| Deed Names | Name on Deed |
|---|---|
| Record Updated | Sep 20, 2026 |
The 2025 property tax bill for 604 Alta Ave was $3,187 with a homeowner's exemption.
Source: San Mateo County assessment roll, as of July 15, 2026
| Type | Name |
|---|---|
| State | California |
| County | San Mateo County |
| Municipality | San Mateo City |
| Elementary School District | San Mateo-Foster City Elementary School District (KG - 08) |
| Secondary School District | San Mateo Union High School District (09 - 12) |
| Year | Tax Bill | Assessed Value | Assessed Market Value |
|---|---|---|---|
| 2026 | $113,242 (+2%) Land $38,714 Building $74,528 | ||
| 2025 | $3,187.00 Homeowner's exemption | $111,022 Land $37,955 Building $73,067 | |
| 2023 | $2,870.00 (-16.42%) Homeowner's exemption | $106,713 Land $36,482 Building $70,231 | $1,742,310 |
| 2022 | $3,434.00 |
Assessed value and assessed market value are set for property tax purposes and are not market price estimates.
FEMA maps place 604 Alta Ave in Zone X, an area of minimal flood risk, though there have been 1 flood claim nearby since 1979.
Source: FEMA National Flood Hazard Layer, effective September 10, 2026 · OpenFEMA NFIP redacted claims and policies, as of September 2026
| FEMA Flood Zone | Zone X minimal risk |
|---|---|
| Flood Insurance Requirement | Not required lenders may require it |
| Nearby Flood Policies | 1 in force |
| Nearby Flood Claims | 1 (1979) |
| Most Recent Claim | Apr 1979 · rainfall accumulation |
Values are read at the parcel center point; flood claims are located to the census block group, not this parcel; lenders make the official flood determination.
The area around 604 Alta Ave has no burnable land within ember reach, so its wildfire risk is not rated.
Source: USDA Forest Service Wildfire Risk to Communities (2nd edition), as of 2024
| Wildfire Risk | Not rated no burnable land within ember reach |
|---|
Values cover an area roughly 900 ft across, not the parcel itself; insurers use their own ratings.
Source: EPA Safe Drinking Water Information System, as of September 2026
| Water System | CALIFORNIA WATER SERVICE - SAN MATEO private · serves 103,536 people · EPA ID CA4110008 |
|---|---|
| Water Source | Purchased surface water from SAN FRANCISCO REGIONAL WATER SYSTEM |
| Last State Inspection | Mar 2025 |
| Lead | 4 ppb (2023–2025) action level 15 ppb |
| Water Quality | None last 10 years |
|---|---|
| Treatment and Procedure | None last 10 years |
| Monitoring and Reporting | None last 3 years |
Results are for the whole water system, not water tested at this address; lead at the tap also depends on the building's own pipes.
Source: FCC Broadband Data Collection, based on 799 locations within half a mile, as of December 31, 2025
| Provider | Max Down / Up (Mbps) |
|---|---|
| Sonic Telecom Fiber | 10,000 / 10,000 |
| AT&T Fiber · Fixed Wireless, DSL in parts of the area | 5,000 / 5,000 |
| Xfinity Cable | 2,000 / 250 |
| Astound Broadband Cable | 1,500 / 50 |
May also be available: Etheric Networks, GeoLinks, T-Mobile, Verizon.
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