Silongkoyo, California
29 topographic sheets cover this place, the earliest surveyed in 1891 and the latest in 1994. It stands in the Quincy census division. It lies in ZIP code area 95971. It lies near Boyle Ravine. The Survey maps it on the Quincy quadrangle. It stands 3,435 feet above sea level. The federal gazetteer marks this settlement historical: it is no longer a populated place, though the surveys that recorded it still are.
Then and now
1891 to 1994The same ground, surveyed 103 years apart. Drag the handle to wipe between them. Both sheets are United States Geological Survey originals; neither has been altered.


Topographic sheets covering this place
12 surveys from 29 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.
- 1891 USGS Downieville quadrangle1:125000
- 1893 USGS Downieville quadrangle1:125000
- 1895 USGS Downieville quadrangle1:125000
- 1896 USGS Downieville quadrangle1:125000
- 1897 USGS Downieville quadrangle1:125000, 7 printings
- 1950 USGS Quincy quadrangle1:24000, 5 printings
- 1951 USGS Quincy quadrangle1:62500, 3 printings
- 1951 USGS Quincy quadrangle1:24000, 2 printings
- 1958 USGS Chico quadrangle1:250000, 4 printings
- 1960 USGS Chico quadrangle1:250000
- 1979 USGS Portola quadrangle1:100000, 2 printings
- 1994 USGS Quincy quadrangle1:24000
Fires near this place
278 since 1992Regional context, not property-specific evidence. The federal wildfire occurrence database lists 278 fires within 5 miles of Silongkoyo (historical) between 1992 and 2020, burning about 5,087 acres in total. 71 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 | 74 |
| Natural | 71 |
| Debris and open burning | 39 |
| Equipment and vehicle use | 26 |
| Recreation and ceremony | 17 |
| Arson/incendiarism | 16 |
| Misuse of fire by a minor | 8 |
| Other causes | 8 |
| Railroad operations and maintenance | 7 |
| Power generation/transmission/distribution | 6 |
| Smoking | 6 |
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 1994 | Recreation and ceremony | under an acre | Plumas National Forest | BRANCH |
| 7 September 1997 | Missing data/not specified/undetermined | under an acre | Plumas National Forest | RANGE |
| 7 September 1997 | Missing data/not specified/undetermined | under an acre | Plumas National Forest | WAPUNSIE |
| 5 September 2017 | Natural | under an acre | Plumas National Forest | ROCK |
| 5 September 2007 | Power generation/transmission/distribution | under an acre | Plumas National Forest | POLE |
| 5 September 2005 | Equipment and vehicle use | under an acre | Plumas National Forest | VALLEY |
| 3 September 2003 | Natural | under an acre | Plumas National Forest | TRESTLE |
| 3 September 2001 | Missing data/not specified/undetermined | under an acre | Plumas National Forest | EAST |
Settlements close enough to share some of these fires:
Mines and quarries near this place
10 of 64 shownRegional context, not property-specific evidence. The federal mineral resources record lists 64 workings within 5 miles of Silongkoyo (historical): 21 unknowns, 16 occurrences, 15 past producers, 7 producers. 7 still produce. What was taken out: Gold, Sand and Gravel, Construction, Chromium, Nickel. 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 |
|---|---|---|---|---|
| Feather River Travertine Marble Qry | Marble, Dimension | Producer | ||
| Pacific Portland Cement Co | Stone, Crushed/Broken | Past Producer | ||
| Rock Cr Deposits | Manganese | Unknown | ||
| Meldick | Gold, Silver | Past Producer | ||
| Missing Link | Gold, Silver | Past Producer | ||
| Rock Creek | Nickel | Occurrence | 1957 | |
| Rock Creek | Nickel | Unknown | ||
| Cattle Spring Claims Nos. 1, 2 | Chromium | Past Producer | 1940, 1943 | |
| Cattle Springs Claim No 1 & 2 | Chromium | Occurrence | ||
| Cough Group | Chromium | Past Producer | 1941, 1943 |
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 |
|---|---|---|---|
| Quincy | 0.1 miles | 29 | |
| Cedar Mill | 1.3 miles | 29 | |
| East Quincy | 2.5 miles | 29 | |
| Quincy Junction | 3.1 miles | 29 | |
| Keddie | 5.5 miles | 24 | |
| Massack | 5.8 miles | 27 | |
| Spanish Ranch | 6.0 miles | 23 | |
| Meadow Valley | 6.1 miles | 23 |
Elsewhere
Matched on this settlement's Geographic Names Information System number rather than its name, so it cannot be a different place of the same name in another state.
| Wikipedia article on Silongkoyo (historical) | An encyclopaedic summary. Its text is share-alike, so it is linked here rather than copied. |
| Wikidata item Q7515530 | The structured record the population and elevation above come from. Public domain (CC0). |
Provenance
This settlement is recorded in the Geographic Names Information System as feature 1701411. 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.











