Marin County property record for 528 Northern Ave, Mill Valley, CA 94941
| Property Type | Duplex |
|---|---|
| Details | 4 bd · 4 ba · 1,984 sqft · built 1950 |
| Lot Size | 0.276 acres (12,000 sqft) |
| Owner | Trust Name on File |
| Tax Bill | $13,536 (2025) |
| Flood Zone | Zone X (minimal risk) |
| APN | 049-091-05 |
| Primary APN | 049-091-05 |
|---|
| Bedrooms | 4 Beds |
|---|---|
| Full Baths | 4 Baths |
| Total Rooms | 4 Rooms |
| Units | 2 Units |
| Stories | 1 Story |
| Building Area | 1,984 sqft Living Area |
| Basement Area | 128 sqft |
| Fireplaces | 1 Fireplace |
| Fireplace | Fireplace |
| Year Built | Built 1950 |
|---|---|
| Effective Year Built | Effective 1960 |
| Architectural Style | Contemporary |
| Exterior Material | Wood Siding |
| Construction Type | Frame |
| Roof Material | Composition Shingle |
| Lot Area | 12,000 sqft (0.276 acres) |
| Deck Area | Deck Area |
| Heating System | Central |
|---|---|
| Sewer | Municipal |
| Water Source | Commercial |
| Street Address | 528 NORTHERN AVE |
|---|---|
| City | MILL VALLEY |
| State | CA |
| Zip | 94941-3781 |
| Property Category | Residential |
| Property Type | Residential > Multi-Unit > Duplex |
| Legal Lot Number | 5,6 |
| Jurisdiction | MARIN CA |
| Township / Civil Division | SOUTHEAST MARIN |
| Census Block Group | 2 |
| Census Block | 2001 |
| Census Tract | 128100 |
528 Northern Ave, a duplex, is held in a trust since August 1995.
Source: Marin County records, as of July 13, 2026
| Owner of Record | Trust Name on File |
|---|---|
| Mailing Address | 1850 CALISTOGA RD, SANTA ROSA, CA 95404-9644 |
| 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 |
|---|---|
| Last Transfer Date | Aug 16, 1995 |
| Transfer Doc | 0000039564 |
| Record Updated | Sep 20, 2026 |
The 2025 property tax bill for 528 Northern Ave was $13,536.
Source: Marin County assessment roll, as of July 13, 2026
| Type | Name |
|---|---|
| State | California |
| County | Marin County |
| Elementary School District | Mill Valley Elementary School District (KG - 08) |
| Secondary School District | Tamalpais Union High School District (09 - 12) |
| Year | Tax Bill | Assessed Value |
|---|---|---|
| 2026 | $531,087 (+2%) Land $291,242 Building $239,845 | |
| 2025 | $13,536.00 | $520,675 Land $285,532 Building $235,143 |
| 2023 | $12,815.00 (+6.81%) | $500,459 Land $274,446 Building $226,013 |
| 2022 | $11,998.00 |
Assessed value is set for property tax purposes and is not a market price estimate.
FEMA maps place 528 Northern Ave in Zone X, an area of minimal flood risk, though there have been 6 flood claims nearby since 1982.
Source: FEMA National Flood Hazard Layer, effective October 18, 2023 · 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 |
| Community Rating System | Class 6 (20% premium discount) |
| Nearby Flood Policies | 6 in force |
| Nearby Flood Claims | 6 (1982–2019) |
| Claims Outside the SFHA | 3 of 6 |
| Most Recent Claim | Feb 2019 · Severe Winter Storms, Flooding, Landslides, And Mudslides |
| Claims by Event |
|
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.
Wildfire risk around 528 Northern Ave is low, with a 0.04% annual chance of wildfire.
Source: USDA Forest Service Wildfire Risk to Communities (2nd edition), as of 2024
| Wildfire Risk | Low lower than 66% of the US · lower than 80% of California |
|---|---|
| Wildfire Likelihood | 0.04% annual chance |
| Exposure | Indirect within ember reach |
| Adjoins Burnable Land | Yes |
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 | MARIN MUNICIPAL WATER DISTRICT serves 188,116 people · EPA ID CA2110002 |
|---|---|
| Water Source | Surface water |
| Last State Inspection | Aug 2023 |
| Lead | Under 1 ppb (2019–2021) 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. This system sells water to local utilities; the supplier billing this address may be one of them.
Source: FCC Broadband Data Collection, based on 496 locations within half a mile, as of December 31, 2025
| Provider | Max Down / Up (Mbps) |
|---|---|
| AT&T Fiber · DSL in parts of the area | 5,000 / 5,000 |
| Xfinity Cable | 2,000 / 250 |
May also be available: T-Mobile, Unwired, Verizon.
5G and 4G LTE (outdoors only)
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