Portola Hills, California
47 topographic sheets cover this place, the earliest surveyed in 1901 and the latest in 1997. It stands in the Irvine-Lake Forest census division. It lies in ZIP code area 92679. The Survey maps it on the Lake Forest quadrangle.
Then and now
1901 to 1997The same ground, surveyed 96 years apart. Drag the handle to wipe between them. Both sheets are United States Geological Survey originals; neither has been altered.


Compare 1901 against another survey:
Topographic sheets covering this place
17 surveys from 47 printed sheetsMatched by testing this settlement's coordinate against the published boundary of every sheet in the United States Geological Survey's historical collection. Each opens the scanned sheet at the Survey.
- 1901 USGS Southern California Sheet No. 1 quadrangle1:250000, 6 printings
- 1902 USGS Corona quadrangle1:125000, 7 printings
- 1904 USGS Southern California Sheet No. 1 quadrangle1:250000, 2 printings
- 1935 USGS El Toro quadrangle1:31680, 4 printings
- 1942 USGS Santiago Peak quadrangle1:62500, 3 printings
- 1947 USGS Santa Ana quadrangle1:250000
- 1949 USGS El Toro quadrangle1:24000, 2 printings
- 1949 USGS Santa Ana quadrangle1:250000
- 1950 USGS El Toro quadrangle1:24000, 2 printings
- 1956 USGS Santa Ana quadrangle1:250000
- 1959 USGS Santa Ana quadrangle1:250000, 3 printings
- 1960 USGS Santa Ana quadrangle1:250000, 2 printings
- 1965 USGS Santa Ana quadrangle1:250000
- 1968 USGS El Toro quadrangle1:24000, 9 printings
- 1974 USGS El Toro quadrangle1:24000
- 1983 USGS Santa Ana quadrangle1:100000
- 1997 USGS El Toro quadrangle1:24000
Fires near this place
109 since 1992Regional context, not property-specific evidence. The federal wildfire occurrence database lists 109 fires within 5 miles of Portola Hills between 1992 and 2020, burning about 7,597 acres in total. 3 started naturally. 21 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 | 39 |
| Arson/incendiarism | 21 |
| Equipment and vehicle use | 20 |
| Misuse of fire by a minor | 8 |
| Smoking | 6 |
| Recreation and ceremony | 6 |
| Power generation/transmission/distribution | 4 |
| Natural | 3 |
| Fireworks | 1 |
| Other causes | 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 |
|---|---|---|---|---|
| 9 September 2011 | Missing data/not specified/undetermined | 1.0 acres | Orange County Fire Authority | not named |
| 7 September 2006 | Equipment and vehicle use | under an acre | Cleveland National Forest | LIVEOAK |
| 3 September 2005 | Recreation and ceremony | under an acre | Cleveland National Forest | POOL |
| 27 September 2010 | Missing data/not specified/undetermined | under an acre | California Department of Forestry & Fire Protection | not named |
| 26 September 2005 | Equipment and vehicle use | under an acre | Cleveland National Forest | DOVE |
| 26 September 1995 | Missing data/not specified/undetermined | under an acre | Cleveland National Forest | POTSIE |
| 25 September 2004 | Missing data/not specified/undetermined | 14 acres | Orange County Fire Authority | SANTIAGO FIRE |
| 25 September 2004 | Equipment and vehicle use | 14 acres | Riverside Unit | STATE FIRE |
Settlements close enough to share some of these fires:
Mines and quarries near this place
10 of 20 shownRegional context, not property-specific evidence. The federal mineral resources record lists 20 workings within 5 miles of Portola Hills: 10 past producers, 6 producers, 2 occurrences, 1 prospect. 6 still produce. What was taken out: Clay, Sand and Gravel, Construction, Stone, Crushed/Broken, Gold. Distance is straight-line from the map coordinates, so a quarry counted here may appear on a neighbouring settlement's page as well.
| Where | Site | Commodity | Status | Recorded |
|---|---|---|---|---|
| Baker Ranch Extension | Stone, Crushed/Broken | Producer | ||
| Blue Light | Lead, Zinc, Silver, Copper, Gold | Past Producer | Pyrite, Sphalerite | |
| Hicks Canyon Prospect | Fire Clay (Refractory) | Occurrence | ||
| Shirley Mine | Gold | Prospect | ||
| Silverado-Santa Rosa | Silver | Producer | ||
| Wilhunt Mines | Lead, Gold, Silver | Past Producer | ||
| El Toro Pit | Sand and Gravel, Construction | Producer | ||
| Gravel Pits | Sand and Gravel, Construction | Past Producer | ||
| Ike Arnold Mine and Washing Plant | Clay, Sand and Gravel, Construction | Past Producer | ||
| Sully-Miller Contracting Co. | Sand and Gravel, Construction | Past Producer |
Storms near this place
1 since 1993Regional context, not property-specific evidence. The National Weather Service names Portola Hills in 1 storm report in 1993: 1 tornado. The reports record 2 injuries. 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 |
|---|---|---|---|---|
| November 1993 | Tornado (F0) | Portola Hills | 2 hurt, $1,000 | A small tornado overturned a mobile home. |
Nearest settlements
The eight closest, with where each one stands in the county. Distances are straight-line, computed from the Geographic Names Information System coordinates.
| Map | Place | Distance | Sheets |
|---|---|---|---|
| Upper Aliso | 0.8 miles | 37 | |
| Rancho Trabuco | 1.6 miles | 37 | |
| Foothill Ranch | 1.7 miles | 47 | |
| Modjeska | 2.1 miles | 47 | |
| Trabuco Canyon | 2.5 miles | 37 | |
| Rancho Santa Margarita | 3.0 miles | 37 | |
| El Toro | 3.6 miles | 47 | |
| Robinson Ranch | 3.7 miles | 37 |
Provenance
This settlement is recorded in the Geographic Names Information System as feature 1765683. The sheet list is computed by point-in-boundary test against the United States Geological Survey's historical topographic inventory. Both are works of the United States government and carry no copyright under 17 U.S.C. 105.
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.
















