331 Mount Sierra Pl, Clayton, CA 94517 Property Records

Contra Costa County property record for 331 Mount Sierra Pl, Clayton, CA 94517

Property Summary

Property Type	Single Family Home
Details	4 bd · 2 ba · 2,325 sqft · built 1979
Lot Size	0.225 acres (9,785 sqft)
Owner	Company Name on Record
Tax Bill	$5,809 (2025)
Flood Zone	Zone X (minimal risk)
APN	`119-510-005`

Property Details

APN / Parcel Number

Primary APN	`119-510-005`
Alternative APN	`119-510-005-0`

Interior

Bedrooms	4 Beds
Full Baths	2 Baths
Total Rooms	11 Rooms
Stories	1 Story
Building Area	2,325 sqft Living Area
1st Floor Area	2,325 sqft

Exterior

Year Built	Built 1979
Effective Year Built	Effective 1980
Architectural Style	Cluster
Lot Area	9,785 sqft (0.225 acres)
Garage Type	Attached
Garage Area	706 sqft
Parking Spaces	2 Parking Spaces

Location & Zoning

Street Address	331 MT SIERRA PL
City	CLAYTON
State	CA
Zip	94517-1615
Property Category	Residential
Property Type	Residential > Single Family > Home
Legal Description	T04018 L0005 B EX MR
Legal Tract	04018
Legal Lot Number	5
Jurisdiction	CONTRA COSTA CA
Township / Civil Division	CENTRAL CONTRA COSTA
Census Block Group	4
Census Block	4000
Census Tract	355306

Owner

Source: Contra Costa County records, as of July 14, 2026

Owner names and exact recorded amounts shown locked on this page are available instantly with a free trial.

Owner of Record	Company Name on Record
Mailing Address	331 MT SIERRA PL, CLAYTON, CA 94517-1615
Occupancy	Owner Occupied
Owner Type	Company
Vesting	Trust

Deeds, Mortgages & Sale History

Assessor's Deed Record

Deed Names	Name on Deed
Last Transfer Date	Nov 7, 2007
Transfer Doc	0000311493
Record Updated	Sep 20, 2026

Tax Assessment & Valuation

Source: Contra Costa County assessment roll, as of July 14, 2026

Property Jurisdictions

Type	Name
State	California
County	Contra Costa County
Municipality	Clayton City
Unified School District	Mount Diablo Unified School District (KG - 12)

Tax Bill & Assessment History

Year	Tax Bill	Assessed Value
2026		$419,157 (+2%) Land $113,488 Building $305,669
2025	$5,809.00 (+4.95%) Homeowner's exemption	$410,939 (+4.04%) Land $111,263 Building $299,676
2023	$5,535.00 (+1.67%) Homeowner's exemption	$394,984 Land $106,944 Building $288,040
2022	$5,444.00

Assessed value is set for property tax purposes and is not a market price estimate.

Flood

Source: FEMA National Flood Hazard Layer, effective October 12, 2026

FEMA Flood Zone	Zone X minimal risk
Nearest Special Flood Hazard Area	Zone AE, within 500 ft
Flood Insurance Requirement	Not required lenders may require it

Values are read at the parcel center point; lenders make the official flood determination.

Wildfire

Source: USDA Forest Service Wildfire Risk to Communities (2nd edition), as of 2024

Wildfire Risk	High above 86% of the US · above 66% of California
Wildfire Likelihood	0.8% 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.

Drinking Water

Source: EPA Safe Drinking Water Information System, as of September 2026

Water System	CONTRA COSTA WATER DISTRICT serves 210,500 people · EPA ID CA0710003
Water Source	Surface water
Last State Inspection	Jan 2022
Lead	Under 1 ppb (2026–2028) action level 15 ppb

Violations Reported to EPA

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.

Internet Providers

Source: FCC Broadband Data Collection, based on 86 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
Verizon Fixed Wireless	300 / 20
T-Mobile Fixed Wireless	100 / 20