Alameda County property record for 321 Mountain Ave, Piedmont, CA 94611
| Property Type | Single Family Home |
|---|---|
| Details | 5 bd · 5.5 ba · 7,495 sqft · built 1985 |
| Lot Size | 1.15 acres (50,490 sqft) |
| Owner | Company Name on File |
| Tax Bill | $81,753 (2025) |
| Flood Zone | Zone X (minimal risk) |
| APN | 51-4701-52 |
| Primary APN | 51-4701-52 |
|---|---|
| Alternative APN |
|
| Bedrooms | 5 Beds |
|---|---|
| Full Baths | 5.5 Baths |
| Half Baths | 1 Half Bath |
| Total Rooms | 14 Rooms |
| Stories | 3 Stories |
| Building Area | 7,495 sqft Living Area |
| Year Built | Built 1985 |
|---|---|
| Effective Year Built | Effective 1985 |
| Architectural Style | L-Shape |
| Construction Type | Wood |
| Lot Area | 50,490 sqft |
| Street Address | 321 MOUNTAIN AVE |
|---|---|
| City | PIEDMONT |
| State | CA |
| Zip | 94611-3507 |
| Property Category | Residential |
| Property Type | Residential > Single Family > Home |
| Legal Description | LOT: 00008 BLK: MP: 0014 PAGE: 0012 ;LOT: 00009 BLK: MP: 0014 PAGE: 0012 |
| Legal Lot Number | 8-9 |
| Jurisdiction | ALAMEDA CA |
| Township / Civil Division | OAKLAND |
| Census Block Group | 5 |
| Census Block | 5008 |
| Census Tract | 426100 |
321 Mountain Ave, a single family home, is owned by a company.
Source: Alameda County records, as of August 5, 2026
| Owner of Record | Company Name on File |
|---|---|
| Mailing Address | 3758 GRAND AVE, OAKLAND, CA 94610-1506 |
| Owner Type | Company |
| Vesting | Company |
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 321 Mountain Ave was $81,753.
Source: Alameda County assessment roll, as of August 5, 2026
| Type | Name |
|---|---|
| State | California |
| County | Alameda County |
| Municipality | Piedmont City |
| Unified School District | Piedmont City Unified School District (KG - 12) |
| Year | Tax Bill | Assessed Value | Assessed Market Value |
|---|---|---|---|
| 2026 | $6,188,874 (+2%) Land $1,856,662 Building $4,332,212 | ||
| 2025 | $81,753.00 | $6,067,530 Land $1,820,259 Building $4,247,271 | |
| 2023 | $77,741.00 | $5,831,944 Land $1,749,583 Building $4,082,361 | $5,672,430 |
Assessed value and assessed market value are set for property tax purposes and are not market price estimates.
FEMA maps place 321 Mountain Ave in Zone X, an area of minimal flood risk, though there have been 3 flood claims nearby since 1983.
Source: FEMA National Flood Hazard Layer, effective May 25, 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 | 4 in force |
| Nearby Flood Claims | 3 (1983–1998) |
| Claims Outside the SFHA | 1 of 3 |
| Most Recent Claim | Jan 1998 · other causes |
| 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.
No wildfire likelihood is modeled around 321 Mountain Ave, 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 wildfire likelihood modeled here |
|---|
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 | EAST BAY MUD serves 1,468,000 people · EPA ID CA0110005 |
|---|---|
| Water Source | Surface water |
| Last State Inspection | Dec 2021 |
| Lead | Under 1 ppb (2022–2024) 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 636 locations within half a mile, as of December 31, 2025
| Provider | Max Down / Up (Mbps) |
|---|---|
| Sonic Telecom Fiber | 10,000 / 10,000 |
| Xfinity Cable | 2,000 / 250 |
| Unwired Fixed Wireless | 300 / 25 |
| Etheric Networks Fixed Wireless | 250 / 100 |
May also be available: AT&T, GeoLinks, T-Mobile, Verizon.
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