21604 Lost River Dr, Diamond Bar, CA 91765 Property Records

Los Angeles County property record for 21604 Lost River Dr, Diamond Bar, CA 91765

Property Summary

Property Type	Single Family Home
Details	4 bd · 2 ba · 1,288 sqft · built 1963
Lot Size	0.19 acres (8,291 sqft)
Owner	Individual Name on File
Last Sale	$860,000 (Jul 2022)
Tax Bill	$11,282 (2025)
Deeds & Mortgages	Aug 2022 Mortgage Aug 2022 Mortgage + 4 more
Flood Zone	Zone X (minimal risk)
APN	`8285-004-011`

Property Details

APN / Parcel Number

Primary APN	`8285-004-011`

Interior

Bedrooms	4 Beds
Full Baths	2 Baths
Total Rooms	7 Rooms
Stories	1 Story
Building Area	1,288 sqft Living Area
Fireplaces	1 Fireplace
Fireplace	Fireplace

Exterior

Year Built	Built 1963
Effective Year Built	Effective 1968
Architectural Style	Conventional
Exterior Material	Stucco
Construction Type	Wood
Roof Type	Hip
Roof Material	Gravel
Lot Area	8,291 sqft (0.19 acres)

Utilities, Heating & Cooling

Cooling System	Central
Heating System	Central

Location & Zoning

Street Address	21604 LOST RIVER DR
City	DIAMOND BAR
State	CA
Zip	91765-3145
Property Category	Residential
Property Type	Residential > Single Family > Home
Local Zoning Code	LCR171/2
Legal Description	TRACT NO 25987 LOT 111
Legal Subdivision	25987
Legal Tract	25987
Legal Block	1
Legal Lot Number	111
Jurisdiction	LOS ANGELES CA
Township / Civil Division	EAST SAN GABRIEL VALLEY
Census Block Group	1
Census Block	1002
Census Tract	403325

Owner

21604 Lost River Dr is owned and occupied by an individual who bought it in July 2022.

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

Owner of Record	Individual Name on File
Mailing Address	21604 LOST RIVER DR, DIAMOND BAR, CA 91765-3145
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.

Deeds, Mortgages & Sale History

Date	Document
Aug 30, 2022	Deed of Trust, Mortgage · Conventional Mortgage BAY VALLEY MORTGAGE GROUP
Aug 26, 2022	Deed of Trust, Mortgage · Conventional Mortgage MISSION LOANS LLC
Jul 20, 2022	Grant Deed, Transfer OLD REPUBLIC TITLE, OLD REPUBLIC TITLE COMPANY
Jun 8, 2022	Affidavit of Death of Trustee, Transfer
Mar 11, 2022	Affidavit of Death of Trustee, Transfer
Jul 9, 2021	Intrafamily Transfer, Transfer

Assessor's Deed Record

Deed Names	Name on Deed
Last Sale	Jul 20, 2022 · Amount on File
Deed Sale	Jul 20, 2022 · Amount on File
Deed Document Number	2022741222
Prior Transfer Date	Jun 11, 2021
Prior Transfer Doc	0001068498
Record Updated	Oct 29, 2026

August 2022: Deed of Trust, Mortgage

Document Type	Deed of Trust
Jurisdiction	LOS ANGELES CA
Property Address	21604 LOST RIVER DR, DIAMOND BAR, CA 91765-3145
Transaction Type	Mortgage
Record Updated	Sep 9, 2022
Title Company	PACIFIC COAST TITLE COMPANY

Transferred To (Grantee/Buyer)

Name	Verified Name
Address	2266 EVERGREEN SPRINGS DR, DIAMOND BAR, CA 91765-3125

Mortgage

Document Number	0000858933
Date	Aug 30, 2022
Instrument	22-0858933

Lender

Name	BAY VALLEY MORTGAGE GROUP
Type	Mortgage Company
Address	GARDEN GROVE, CA 92841

Agreement

Type	Conventional Mortgage
Amount	Amount on Record
Term	181 Months
Due	Sep 1, 2037

August 2022: Deed of Trust, Mortgage

Document Type	Deed of Trust
Jurisdiction	LOS ANGELES CA
Property Address	21604 LOST RIVER DR, DIAMOND BAR, CA 91765-3145
Transaction Type	Mortgage
Record Updated	Sep 2, 2022
Title Company	PACIFIC COAST TITLE COMPANY

Transferred To (Grantee/Buyer)

Name	Verified Name
Address	211-213 E 105TH ST, LOS ANGELES, CA 90003

Mortgage

Document Number	0000853367
Date	Aug 26, 2022
Instrument	22-0853367

Lender

Name	MISSION LOANS LLC
Type	Mortgage Company
Address	IRVINE, CA 92612

Agreement

Type	Conventional Mortgage
Amount	Amount on Record
Term	361 Months
Due	Sep 1, 2052

July 2022: Grant Deed, Transfer

Document Type	Grant Deed
Jurisdiction	LOS ANGELES CA
Recording Date	Jul 20, 2022
Property Address	21604 LOST RIVER DR, DIAMOND BAR, CA 91765-3145
Document Number	0000741222
Map Reference	MB 694 PG 24-28
Instrument Date	Jul 13, 2022
Instrument	22-0741222
Transaction Type	Transfer
Record Updated	Jul 29, 2022
Title Company	OLD REPUBLIC TITLE, OLD REPUBLIC TITLE COMPANY

Transaction

Amount	Amount on Record
Tax	$0.00
Amount Accuracy	Rounded by County
Additional	Arm's Length

Transferred From (Grantor/Seller)

Name	Verified Name

Transferred To (Grantee/Buyer)

Name	Verified Name
Address	21604 LOST RIVER DR, DIAMOND BAR, CA 91765-3145

June 2022: Affidavit of Death of Trustee, Transfer

Document Type	Affidavit of Death of Trustee
Jurisdiction	LOS ANGELES CA
Recording Date	Jun 8, 2022
Property Address	21604 LOST RIVER DR, DIAMOND BAR, CA 91765-3145
Document Number	0000611752
Map Reference	MB 694 PG 24-28
Instrument Date	May 20, 2022
Instrument	22-0611752
Transaction Type	Transfer
Record Updated	Jun 7, 2023

Transaction

Tax	$0.00
Amount Accuracy	No Consideration Stated
Additional	Arm's Length

Transferred From (Grantor/Seller)

Name	Verified Name

Transferred To (Grantee/Buyer)

Name	Verified Name
Relationship	Revocable Living Trust
Address	946 GRANT ST, CALIMESA, CA 92320-1410

March 2022: Affidavit of Death of Trustee, Transfer

Document Type	Affidavit of Death of Trustee
Jurisdiction	LOS ANGELES CA
Recording Date	Mar 11, 2022
Property Address	21604 LOST RIVER DR, DIAMOND BAR, CA 91765-3145
Document Number	0000286819
Map Reference	MB 694 PG 24-28
Instrument Date	Feb 18, 2022
Instrument	22-0286819
Transaction Type	Transfer
Record Updated	Jun 7, 2023

Transaction

Tax	$0.00
Amount Accuracy	No Consideration Stated
Additional	Arm's Length

Transferred From (Grantor/Seller)

Name	Verified Name

Transferred To (Grantee/Buyer)

Name	Verified Name
Relationship	Revocable Living Trust
Address	946 GRANT ST, CALIMESA, CA 92320-1410

July 2021: Intrafamily Transfer, Transfer

Document Type	Intrafamily Transfer
Jurisdiction	LOS ANGELES CA
Recording Date	Jul 9, 2021
Property Address	21604 LOST RIVER DR, DIAMOND BAR, CA 91765-3145
Document Number	0001068498
Map Reference	MB 694 PG 24-28
Instrument Date	Jun 11, 2021
Instrument	21-1068498
Transaction Type	Transfer
Record Updated	Jun 7, 2023

Transaction

Tax	$0.00
Amount Accuracy	Transfer Tax Exempt
Additional	Intrafamily Transfer

Transferred From (Grantor/Seller)

Name	Verified Name

Transferred To (Grantee/Buyer)

Name	Verified Name
Relationship	Revocable Trust
Address	21604 LOST RIVER DR, DIAMOND BAR, CA 91765-3145

Tax Assessment & Valuation

The 2025 property tax bill for 21604 Lost River Dr was $11,282.

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		$912,636 (+2%) Land $730,110 Building $182,526
2025	$11,282.00	$894,743 Land $715,795 Building $178,948
2023	$10,552.00 (+640.49%)	$860,000 Land $688,000 Building $172,000
2022	$1,425.00

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

Flood

FEMA maps place 21604 Lost River Dr in Zone X, an area of minimal flood risk.

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

Wildfire risk around 21604 Lost River Dr is low, with a 0.02% 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	0.02% 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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