21534 Lost River Dr, Diamond Bar, CA 91765 Property Records

Los Angeles County property record for 21534 Lost River Dr, Diamond Bar, CA 91765

Property Summary

Property Type	Single Family Home
Details	4 bd · 2 ba · 1,288 sqft · built 1964
Lot Size	0.179 acres (7,777 sqft)
Owner	2 Company Names on Record
Last Sale	$362,000 (Nov 2003)
Tax Bill	$7,197 (2025)
Deeds & Mortgages	Jan 2021 Transfer
Flood Zone	Zone X (minimal risk)
APN	`8285-004-013`

Property Details

APN / Parcel Number

Primary APN	`8285-004-013`

Interior

Bedrooms	4 Beds
Full Baths	2 Baths
Total Rooms	9 Rooms
Stories	1 Story
Building Area	1,288 sqft Living Area
Fireplaces	1 Fireplace
Fireplace	Fireplace

Exterior

Year Built	Built 1964
Effective Year Built	Effective 1965
Architectural Style	Conventional
Exterior Material	Stucco
Construction Type	Wood
Roof Type	Hip
Roof Material	Wood Shingle
Lot Area	7,777 sqft (0.179 acres)
Lot Dimensions	115 ft deep x 67 ft wide

Utilities, Heating & Cooling

Heating System	Central

Location & Zoning

Street Address	21534 LOST RIVER DR
City	DIAMOND BAR
State	CA
Zip	91765-3126
Property Category	Residential
Property Type	Residential > Single Family > Home
Local Zoning Code	LCR171/2
Legal Description	TRACT NO 25987 LOT 113
Legal Subdivision	25987
Legal Tract	25987
Legal Block	1
Legal Lot Number	113
Jurisdiction	LOS ANGELES CA
Township / Civil Division	EAST SAN GABRIEL VALLEY
Census Block Group	1
Census Block	1002
Census Tract	403325

Owner

Source: Los Angeles County records, as of August 25, 2026

Owner names and exact recorded amounts are on file and can be viewed instantly on this page with a free 10-day trial.

Owner of Record	2 Company Names on Record
Mailing Address	21534 LOST RIVER DR, DIAMOND BAR, CA 91765-3126
Occupancy	Owner Occupied
Owner Type	Company
Vesting	Trust, Family Trust

Deeds, Mortgages & Sale History

Assessor's Deed Record

Deed Names	2 Names on Deed
Last Sale	Nov 7, 2003 · Amount on Record
Deed Sale	Nov 7, 2003 · Amount on Record
Prior Sale	Jul 10, 2003 · Amount on Record
Deed Document Number	20033352257
Prior Transfer Date	Nov 6, 1996
Prior Transfer Doc	0002008736
Record Updated	Oct 29, 2026

January 2021: Quit Claim Deed, Transfer

Document Type	Quit Claim Deed
Jurisdiction	LOS ANGELES CA
Recording Date	Jan 11, 2021
Property Address	21534 LOST RIVER DR, DIAMOND BAR, CA 91765-3126
Document Number	0000044177
Instrument Date	Jul 24, 2020
Instrument	44177
Transaction Type	Transfer
Record Updated	Feb 10, 2021
Title Company	ATTORNEY ONLY

Transaction

Tax	$0.00
Additional	Quitclaim Intrafamily Transfer

Transferred From (Grantor/Seller)

Name	Verified Name

Transferred To (Grantee/Buyer)

Name	Verified Name
Relationship	Revocable Trust
Address	21534 LOST RIVER DR DIAMOND BAR CA 917653126, DIAMOND BAR, CA 91765-3126

Tax Assessment & Valuation

Source: Los Angeles County assessment roll, as of August 25, 2026

Property Jurisdictions

Type	Name
State	California
County	Los Angeles County
Municipality	Diamond Bar City
Unified School District	Walnut Valley Unified School District (KG - 12)

Tax Bill & Assessment History

Year	Tax Bill	Assessed Value
2026		$568,570 (+1.99%) Land $356,383 Building $212,187
2025	$7,197.00 (+4.5%) Homeowner's exemption	$557,453 (+4.04%) Land $349,411 Building $208,042
2024	$6,887.00 (+2.44%)
2023	$6,723.00 (+2.14%) Homeowner's exemption	$535,808 Land $335,844 Building $199,964
2022	$6,582.00

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

Flood

Source: FEMA National Flood Hazard Layer, effective September 30, 2026

FEMA Flood Zone	Zone X minimal risk
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	Low lower than 80% of the US · lower than 88% of California
Wildfire Likelihood	0.02% annual chance
Exposure	None beyond ember reach

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	WALNUT VALLEY WATER DISTRICT serves 100,941 people · EPA ID CA1910234
Water Source	Purchased surface water from several systems
Last State Inspection	Jun 2023
Lead	Under 1 ppb (2022–2024) 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 437 locations within half a mile, as of December 31, 2025

Provider	Max Down / Up (Mbps)
Frontier Fiber	7,000 / 7,000
Spectrum Cable	1,000 / 35
AT&T Fixed Wireless	100 / 20
T-Mobile Fixed Wireless	100 / 20

May also be available: GeoLinks, Verizon.

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