Marin County property record for 422 William Ave, Larkspur, CA 94939
| Property Type | Single Family Home |
|---|---|
| Details | 3 bd · 2.5 ba · 1,964 sqft · built 1941 |
| Lot Size | 0.133 acres (5,775 sqft) |
| Owner | Individual Name on File |
| Last Sale | $565,000 (Mar 2002) |
| Tax Bill | $18,866 (2025) |
| Deeds & Mortgages | Oct 2026 Sale |
| Flood Zone | Zone AE (high risk) |
| APN | 021-212-21 |
| Primary APN | 021-212-21 |
|---|
| Bedrooms | 3 Beds |
|---|---|
| Full Baths | 2.5 Baths |
| Half Baths | 1 Half Bath |
| Building Area | 1,964 sqft Living Area |
| Fireplaces | 1 Fireplace |
| Fireplace | Fireplace |
| Year Built | Built 1941 |
|---|---|
| Effective Year Built | Effective 1998 |
| Architectural Style | Contemporary |
| Lot Area | 5,775 sqft (0.133 acres) |
| Garage Area | 264 sqft |
| Parking Spaces | 1 Parking Space |
| Heating System | Central |
|---|
| Street Address | 422 WILLIAM AVE |
|---|---|
| City | LARKSPUR |
| State | CA |
| Zip | 94939-1530 |
| Property Category | Residential |
| Property Type | Residential > Single Family > Home |
| Legal Subdivision | HEATHER GARDENS #2 |
| Legal Lot Number | 84 |
| Jurisdiction | MARIN CA |
| Township / Civil Division | ROSS VALLEY |
| Census Block Group | 1 |
| Census Block | 1005 |
| Census Tract | 120002 |
422 William Ave is owned and occupied by an individual who acquired it in September 2026.
Source: Marin County records, as of October 15, 2026
| Owner of Record | Individual Name on File |
|---|---|
| Mailing Address | 422 WILLIAM AVE, LARKSPUR, CA 94939-1530 |
| Occupancy | Owner Occupied |
| Owner Type | Individual |
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 Sale | Mar 15, 2002 · Amount on File |
| Deed Sale | Mar 15, 2002 · Amount on File |
| Deed Document Number | 200220602 |
| Last Transfer Date | Sep 29, 2026 |
| Transfer Doc | 0000028601 |
| Record Updated | Oct 29, 2026 |
| Document Type | Affidavit |
|---|---|
| Jurisdiction | MARIN CA |
| Recording Date | Oct 6, 2026 |
| Property Address | 422 WILLIAM AVE, LARKSPUR, CA 94939-1530 |
| Document Number | 0000028601 |
| Instrument Date | Sep 29, 2026 |
| Instrument | 202628601 |
| Transaction Type | Transfer |
| Record Updated | Oct 14, 2026 |
| Tax | $0.00 |
|---|---|
| Amount Accuracy | Full Amount Stated |
| Additional |
|
| Name | Verified Name |
|---|
| Name | Verified Name |
|---|---|
| Address | 422 WILLIAM AVE, LARKSPUR, CA 94939-1530 |
The 2025 property tax bill for 422 William Ave was $18,866.
Source: Marin County assessment roll, as of July 13, 2026
| Type | Name |
|---|---|
| State | California |
| County | Marin County |
| Municipality | Larkspur City |
| Elementary School District | Larkspur Elementary School District (KG - 08) |
| Secondary School District | Tamalpais Union High School District (09 - 12) |
| Year | Tax Bill | Assessed Value |
|---|---|---|
| 2026 | $1,339,131 (+2%) Land $753,370 Building $585,761 | |
| 2025 | $18,866.00 | $1,312,879 Land $738,600 Building $574,279 |
| 2023 | $17,830.00 (+1.36%) | $1,261,908 Land $709,925 Building $551,983 |
| 2022 | $17,591.00 |
Assessed value is set for property tax purposes and is not a market price estimate.
FEMA maps place 422 William Ave in Zone AE, a high-risk flood area; flood insurance is required for federally backed loans.
Source: FEMA National Flood Hazard Layer, effective October 18, 2023 · OpenFEMA NFIP redacted claims and policies, as of September 2026
| FEMA Flood Zone | Zone AE high risk |
|---|---|
| 100-Year Floodplain | Yes 1% annual chance |
| Floodway | No |
| Base Flood Elevation | 10.0 ft |
| Flood Insurance Requirement | Required federally backed loans |
| Flood Insurance Cost | Premium on File median of 23 policies |
| Nearby Flood Policies | 23 in force |
| Nearby Flood Claims | 2 (2014–2017) |
| Most Recent Claim | Jan 2017 · Severe Winter Storms, Flooding, And Mudslides |
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 422 William Ave is low, with a 0.01% annual chance of wildfire.
Source: USDA Forest Service Wildfire Risk to Communities (2nd edition), as of 2024
| Wildfire Risk | Low lower than 80% of the US · lower than 88% of California |
|---|---|
| Wildfire Likelihood | 0.01% annual chance |
| Exposure | Direct burnable vegetation |
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 416 locations within half a mile, as of December 31, 2025
| Provider | Max Down / Up (Mbps) |
|---|---|
| Xfinity Cable | 2,000 / 250 |
| Unwired Fixed Wireless | 300 / 25 |
| T-Mobile Fixed Wireless | 100 / 20 |
| AT&T DSL · Fiber in parts of the area | 100 / 20 |
May also be available: Verizon.
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