Leonis Adobe

Listed on the National Register of Historic Places in 1975. 14 historic topographic surveys show this location, the earliest from 1903.

From the record

“The Leonis Adobe is a historic adobe located in what is now Calabasas, California. One of the oldest surviving private residences in Los Angeles County and one of the oldest surviving buildings in the San Fernando Valley, it was built in 1844 and was occupied by the wealthy rancher Miguel Leonis until his death.”
Wikipedia article Leonis Adobe, CC BY-SA 4.0.

One of 616 National Register listings published here for Los Angeles County · listed in 1975 · category: Building.

Sources: the Wikipedia article · the case file at the National Archives · the National Register database, National Park Service

The listing

What is counted as historic. The nomination lists 6 structuress, 2 buildingss as contributing to the listing.
Address. 23537 Calabasas Rd., Calabasas, 91302
When was it listed? May 1975
Category. building
Census division. San Fernando Valley
Architectural style. Monterey Colonial architecture, Queen Anne style
National Register reference number. 75000433 - the number the National Park Service assigned this property when it was listed, and the key its nomination file is catalogued under at the National Archives.

Then and now

1903 to 1979

The ground this property stands on, surveyed 76 years apart. Drag the handle to wipe between them. Both sheets are United States Geological Survey originals; neither has been altered.

Topographic sheet covering Leonis Adobe, surveyed 1979

Topographic sheet covering Leonis Adobe, surveyed 1903

Fires near this property

140 since 1992

Regional context, not property-specific evidence. The federal wildfire occurrence database lists 140 fires within 5 miles of Leonis Adobe between 1992 and 2020, burning about 15,151 acres in total. None started naturally. 16 were recorded as arson. Distance is straight-line from the map coordinates, so a fire counted here may appear on a neighbouring settlement's page as well.

Reported cause	Fires
Missing data/not specified/undetermined	66
Equipment and vehicle use	29
Arson/incendiarism	16
Smoking	9
Misuse of fire by a minor	7
Debris and open burning	5
Power generation/transmission/distribution	4
Fireworks	3
Recreation and ceremony	1

The most recent of them, most recent first, with the day each was reported and the service that recorded it.

Date	Cause	Size	Reported by	Name on the report
7 September 1999	Arson/incendiarism	3.0 acres	Santa Monica Mountains National Recreation Area	MULHOLLAND
6 September 2013	Missing data/not specified/undetermined	under an acre	Los Angeles County Fire Department	not named
6 September 2009	Missing data/not specified/undetermined	under an acre	California Department of Forestry & Fire Protection	not named
6 September 2009	Missing data/not specified/undetermined	under an acre	Santa Monica Mountains National Recreation Area	FREEWAY
30 September 2009	Missing data/not specified/undetermined	1.0 acres	Santa Monica Mountains National Recreation Area	GILLETTE
30 September 2005	Debris and open burning	under an acre	California Department of Forestry & Fire Protection	not named
28 September 2010	Missing data/not specified/undetermined	under an acre	Santa Monica Mountains National Recreation Area	CALABASAS
26 September 2008	Smoking	under an acre	California Department of Forestry & Fire Protection	not named

Every fire recorded in Los Angeles County

Mines and quarries near this property

3 within 5 miles

Regional context, not property-specific evidence. The federal mineral resources record lists 3 workings within 5 miles of Leonis Adobe: 2 past producers, 1 producer. 1 still produces. What was taken out: Stone, Dimension, Stone. Distance is straight-line from the map coordinates, so a quarry counted here may appear on a neighbouring settlement's page as well.

Site	Commodity	Status
Unnamed Location	Stone	Producer
Gilbert	Stone, Dimension	Past Producer
Volcanic Rock	Stone, Dimension	Past Producer

Every working recorded in Los Angeles County

Storms near this property

1 since 1996

Regional context, not property-specific evidence. The National Weather Service names Calabasas, the town this property stands in, in 1 storm report in 1996: 1 lightning. The reports record 1 injury. Each account below is quoted exactly as the forecast office filed it, from the NOAA Storm Events Database, and each date opens the federal record of that event.

When	Event	Place named	Harm	What the report says
March 1996	Lightning	Calabasas	1 hurt	no account filed

Every storm recorded in Los Angeles County

Maps showing this location

14 surveys

United States Geological Survey topographic sheets whose coverage includes this point. Matched by taking the coordinate the National Park Service records for this property, then testing that coordinate against the published boundary of every sheet.

1903 USGS Calabasas quadrangle1:62500 - 8 printings
1903 USGS Camulos quadrangle1:125000 - 5 printings
1928 USGS Dry Canyon quadrangle1:24000
1929 USGS Dry Canyon quadrangle1:24000
1932 USGS Dry Canyon quadrangle1:24000 - 3 printings
1944 USGS Calabasas quadrangle1:62500
1949 USGS Los Angeles quadrangle1:250000 - 2 printings
1952 USGS Calabasas quadrangle1:24000 - 9 printings
1955 USGS Los Angeles quadrangle1:250000
1959 USGS Los Angeles quadrangle1:250000 - 3 printings
1966 USGS Los Angeles quadrangle1:250000
1975 USGS Los Angeles quadrangle1:250000 - 2 printings
1976 USGS Calabasas quadrangle1:24000 - 2 printings
1979 USGS Los Angeles quadrangle1:100000

Listed places nearby

1 within 8 miles

Other National Register properties close enough to walk or drive between, ordered by distance from this one. Both positions come from the same geocoding pass that matched these properties to their map sheets.

Photograph	Property	Distance	Listed
	Minnie Hill Palmer House	7.3 miles	1979

Sources for this property

National Archives record	The nomination case file for reference 75000433 in Record Group 79.
Wikipedia article	Community-written account of this property, licensed CC BY-SA.
Los Angeles County	All 616 listed properties in this county.

Provenance

Listing record. National Park Service National Register of Historic Places, listed-properties dataset, current to 2026-05-22.
Map join. Address geocoded through the United States Census geocoder, then tested against the published boundary of every sheet in the USGS Historical Topographic Map Collection.
How this page is made. Listing fields come from federal records; map-sheet coverage is a labelled coordinate-to-boundary calculation, not a source-field claim.
Wildfire. Short, Karen C. 2022. Spatial wildfire occurrence data for the United States, 1992-2020 [FPA_FOD_20221014]. 6th Edition. Fort Collins, CO: Forest Service Research Data Archive. https://doi.org/10.2737/RDS-2013-0009.6 Collected with United States Government funding and usable without additional permissions or fees.
Mines and quarries. USGS Mineral Resources Data System (MRDS) https://mrdata.usgs.gov/mrds/ A work of the United States government, no copyright under 17 U.S.C. 105.
Storms. NOAA National Centers for Environmental Information, Storm Events Database https://www.ncei.noaa.gov/stormevents/ A work of the United States government, no copyright under 17 U.S.C. 105. Narratives are quoted verbatim from the National Weather Service report and are not edited or summarised.