Marin County property record for 20 Underhill Rd, Mill Valley, CA 94941 · Last verified July 2026
| Property Type | Single Family Home |
|---|---|
| Details | 4 bd · 3.5 ba · 3,433 sqft · built 1967 |
| Lot Size | 0.436 acres (18,995 sqft) |
| Owner | 2 Company Names on File |
| Tax Bill | $21,173 (2025) |
| Flood Zone | Zone X (minimal risk) |
| APN | 033-153-16 |
| Primary APN | 033-153-16 |
|---|---|
| Alternative APN |
|
| Bedrooms | 4 Beds |
|---|---|
| Full Baths | 3.5 Baths |
| Half Baths | 1 Half Bath |
| Total Rooms | 10 Rooms |
| Building Area | 3,433 sqft Living Area |
| Fireplaces | 1 Fireplace |
| Fireplace | Fireplace |
| Year Built | Built 1967 |
|---|---|
| Effective Year Built | Effective 1979 |
| Lot Area | 18,995 sqft (0.436 acres) |
| Garage Area | 588 sqft |
| Parking Spaces | 2 Parking Spaces |
| Pool Area | 512 sqft |
| Deck Area | 44 sqft |
| Patio Area | 44 sqft |
| Heating System | Central |
|---|
| Street Address | 20 UNDERHILL RD |
|---|---|
| City | MILL VALLEY |
| State | CA |
| Zip | 94941-1424 |
| Property Category | Residential |
| Property Type | Residential > Single Family > Home |
| Jurisdiction | MARIN CA |
| Township / Civil Division | SOUTHEAST MARIN |
| Census Block Group | 1 |
| Census Block | 1000 |
| Census Tract | 126200 |
Source: Marin County records · APN 033-153-16
Assessment roll updated July 13, 2026 · Last verified July 2026
Owner names and exact recorded amounts shown locked on this page are available instantly with a free trial.
| Owner of Record | 2 Company Names on File |
|---|---|
| Mailing Address | 20 UNDERHILL RD, MILL VALLEY, CA 94941-1424 |
| Occupancy | Owner Occupied |
| Owner Type | Company |
| Vesting | Trust |
| Deed Names | 2 Verified Names on Deed |
|---|---|
| Last Transfer Date | Jun 08, 2006 |
| Transfer Doc | 0000036861 |
| Record Updated | Sep 20, 2026 |
Source: Marin County records · Assessment roll updated July 13, 2026 · Last verified July 2026
| Type | Name |
|---|---|
| State | California |
| County | Marin County |
| Municipality | Mill Valley City |
| Elementary School District | Mill Valley Elementary School District (KG - 08) |
| Secondary School District | Tamalpais Union High School District (09 - 12) |
Assessed value is set for property tax purposes and is not a market price estimate.
| Year | Tax Bill | Assessed Value |
|---|---|---|
| 2026 | $1,704,834 (+2%) Land $574,188 Building $1,130,646 | |
| 2025 | $21,173.00 (+5.53%) Homeowner's exemption | $1,671,413 (+4.04%) Land $562,932 Building $1,108,481 |
| 2023 | $20,064.00 (+1.43%) Homeowner's exemption | $1,606,515 Land $541,074 Building $1,065,441 |
| 2022 | $19,782.00 |
Source: FEMA National Flood Hazard Layer, Marin County (06041C), updated October 18, 2023 · FEMA OpenFEMA NFIP redacted claims and policies, census block group 060411262001, refreshed September 2026 · USDA Forest Service Wildfire Risk to Communities, 2nd edition (2024), fuels as of 2020 · Last verified October 2026
| FEMA Flood Zone | Zone X |
|---|---|
| Special Flood Hazard Area | No |
| Flood Hazard | Minimal |
| 500-Year Floodplain | No |
| Flood Insurance Cost | Premium on Record median of 86 individual NFIP policies nearby |
| Community Rating System | Class 6 (20% premium discount) |
| Nearby Flood Policies | 108 units insured 22 under condo master policies |
| Nearby Flood Claims | 9 (1982–2019) |
| Claims Outside the SFHA | 1 of 9 |
| Most Recent Claim | Feb 2019, other causes, Severe Winter Storms, Flooding, Landslides, And Mudslides |
| Claims By Storm |
|
| Wildfire Risk | Low above 32% of the US · above 19% of California |
|---|---|
| Wildfire Likelihood | About 1 in 3,571 per year |
| Exposure | Indirect within ember reach |
| Adjoins Burnable Land | Yes |
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.
Source: FCC Broadband Data Collection, availability as of December 31, 2025 · Published October 2026 · based on 105 locations within about half a mile of this property
| Provider | Technology | Download / Upload (Mbps) |
|---|---|---|
| Xfinity | Cable | 2,000 / 250 |
| Unwired | Fixed Wireless | 300 / 25 |
May also be available at this address: AT&T. Availability varies by address; speeds are provider-advertised maximums, not measured.
5G and 4G LTE (outdoors only)
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