Thornwood, New York
39 topographic sheets cover this place, the earliest surveyed in 1892 and the latest in 1986. It stands in Mount Pleasant town. It lies in ZIP code area 10594. It stands on Nanny Hagen Brook. The Survey maps it on the White Plains quadrangle. 3,960 people lived here at the 2020 count. It stands 269 feet above sea level.
Then and now
1892 to 1986The same ground, surveyed 94 years apart. Drag the handle to wipe between them. Both sheets are United States Geological Survey originals; neither has been altered.


On record in Thornwood
Buildings and businesses the archive holds for this place. Each opens its own page, with the source record it came from.
On the National Register within a mile 1 record
The National Register names another town for these. They stand within one mile of this settlement's coordinate.
St. John's Episcopal Churchlisted 2017 · 0.9 miles away
Population over time
2 figuresThornwood grew from 3,759 to 3,960 between 2010 and 2020. These are the recorded population figures Wikidata holds for this place, reached through the Geographic Names Information System number this page is keyed on rather than by name, so they belong to this place and not to another of the same name. Most are census counts, but not all are: an early figure may be a founding or settlement estimate, and an estimate published within five years of a census is left out. The change column is computed, and is left blank where more than 20 years separate a figure from the one before it, because a gap that long is not a change between two counts.
| Year | People | Change |
|---|---|---|
| 2010 | 3,759 | |
| 2020 | 3,960 | +201 (+5%) |
Topographic sheets covering this place
15 surveys from 39 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.
- 1892 USGS Tarrytown quadrangle1:62500
- 1893 USGS Tarrytown quadrangle1:62500, 3 printings
- 1902 USGS Tarrytown quadrangle1:62500, 11 printings
- 1932 USGS White Plains quadrangle1:24000
- 1937 USGS Tarrytown quadrangle1:62500
- 1938 USGS White Plains quadrangle1:31680, 3 printings
- 1947 USGS Hartford quadrangle1:250000, 2 printings
- 1947 USGS White Plains quadrangle1:24000
- 1948 USGS Hartford quadrangle1:250000, 2 printings
- 1957 USGS White Plains quadrangle1:24000, 2 printings
- 1961 USGS Hartford quadrangle1:250000
- 1962 USGS Hartford quadrangle1:250000, 3 printings
- 1965 USGS Hartford quadrangle1:250000, 2 printings
- 1967 USGS White Plains quadrangle1:24000, 3 printings
- 1986 USGS Bridgeport quadrangle1:100000, 3 printings
Fires near this place
487 since 2000Regional context, not property-specific evidence. The federal wildfire occurrence database lists 487 fires within 5 miles of Thornwood between 2000 and 2020, burning about 414 acres in total. 75 started naturally. 27 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 | 227 |
| Natural | 75 |
| Recreation and ceremony | 46 |
| Debris and open burning | 34 |
| Smoking | 30 |
| Arson/incendiarism | 27 |
| Equipment and vehicle use | 24 |
| Power generation/transmission/distribution | 19 |
| Misuse of fire by a minor | 5 |
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 |
|---|---|---|---|---|
| 8 September 2010 | Debris and open burning | under an acre | Fire Department of New York | not named |
| 8 September 2007 | Missing data/not specified/undetermined | under an acre | Fire Department of New York | not named |
| 7 September 2007 | Missing data/not specified/undetermined | under an acre | Fire Department of New York | not named |
| 5 September 2014 | Missing data/not specified/undetermined | under an acre | Fire Department of New York | not named |
| 5 September 2008 | Power generation/transmission/distribution | under an acre | Fire Department of New York | not named |
| 4 September 2016 | Smoking | under an acre | Fire Department of New York | N/A |
| 4 September 2014 | Missing data/not specified/undetermined | under an acre | Fire Department of New York | not named |
| 4 September 2013 | Missing data/not specified/undetermined | under an acre | Fire Department of New York | N/A |
Settlements close enough to share some of these fires:
Mines and quarries near this place
10 of 11 shownRegional context, not property-specific evidence. The federal mineral resources record lists 11 workings within 5 miles of Thornwood: 7 past producers, 2 occurrences, 1 plant, 1 producer. 2 still produce. What was taken out: Iron, Lead, Granite, Silver. 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 |
|---|---|---|---|---|
| Armonk Plant | Peat | Past Producer | Peat | |
| Ossining Area | Vanadium, Lead | Occurrence | Vanadinite | |
| Sing Sing Ag Mine | Lead, Silver, Iron, Copper | Past Producer | ||
| Sing Sing Silver Mine | Lead, Copper, Silver, Iron, Chromium, Phosphorus-Phosphates | Past Producer | Chalcocite, Chalcopyrite, Galena, Malachite, Silver | |
| Sparta Copper Deposit | Copper, Lead | Occurrence | ||
| (Facility) Chester Metals Division Refinery | Silver | Plant | ||
| Lake Street Granite Mine | Granite | Producer | ||
| Lake Street Granite Quarry | Granite | Past Producer | Granite | |
| Ackerman's Limonite Mine | Iron | Past Producer | Limonite | |
| Ackerman's Limonite Mine | Iron | Past Producer | Residual |
Storms near this place
17 since 2007Regional context, not property-specific evidence. The National Weather Service names Thornwood in 17 storm reports between 2007 and 2021: 11 flash flood, 3 thunderstorm wind, 2 flood, 1 hail. No death or injury is recorded in these reports. 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 |
|---|---|---|---|---|
| July 2011 | Thunderstorm Wind | Thornwood | $7,500 | Multiple trees were reported down along the Saw Mill River Parkway from near Exit 29 to near Exit 32. |
| May 2018 | Thunderstorm Wind | Thornwood | $5,000 | Reports of numerous trees down around town. |
| August 2009 | Thunderstorm Wind | Thornwood | $1,500 | Wheeler Avenue in Pleasantville was closed due to a downed tree. |
| September 2021 | Flash Flood | Thornwood | - | All lanes were closed northbound due to flooding on the Saw Mill River Parkway between Marble Avenue (Exit 17) and Manville Road in Pleasantville. |
| August 2021 | Flash Flood | Thornwood | - | The Saw Mill River Parkway was closed in both directions due to flooding at Manville Road in Pleasantville. |
| July 2019 | Flash Flood | Thornwood | - | All northbound lanes closed due to flooding on the Saw Mill River Parkway between Marble Avenue (Exit 27) and Bedford Road in Mount Pleasant. |
| July 2019 | Flash Flood | Thornwood | - | The Saw Mill River Parkway was closed northbound at Marble Avenue (Exit 27) and southbound at Manville Road in Pleasantville due to flooding. |
| October 2018 | Flash Flood | Thornwood | - | All lanes were closed in both directions on the Saw Mill River Parkway in Mount Pleasant at Exit 27 (Marble Avenue) due to flooding. |
| August 2017 | Flash Flood | Thornwood | - | The northbound Saw Mill River Parkway was closed at Exit 27 in Sherman Park due to flooding. |
| August 2017 | Hail | Thornwood | - | Golfball size hail was reported in Thornwood by a trained spotter. |
| July 2017 | Flash Flood | Thornwood | - | The Saw Mill Parkway was closed northbound at Marble Avenue in Pleasantville. |
| December 2012 | Flash Flood | Thornwood | - | In Pleasantville, the Saw Mill River Pkwy. was closed in both directions between the Taconic State Pkwy. and exit 29 (Manville Rd.) due to flooding. |
| December 2011 | Flood | Thornwood | - | The Saw Mill River Pkwy. was closed between Marble Ave. and Manville Rd. due to flooding with many vehicles stranded in high water. Another vehicle was also stranded in high water on the Saw Mill River Pkwy. in Mount Pleasant. |
| March 2010 | Flood | Thornwood | - | The Saw Mill River Pkwy. was closed in both directions between Manville Rd. and Marble Ave. in Pleasantville due to flooding. |
| June 2009 | Flash Flood | Thornwood | - | Both directions of the Bronx River Pkwy. from the Sprain Brook Pkwy. in Yonkers to Route 119/Main St. in White Plains were closed due to flooding. One car was submerged in high water (approximately 3 to 4 ft high) on the parkway in Bronxville. Both directions of the Hutchinson River Pkwy. between Boston Post Rd. and the Cross County Pkwy. and the Saw Mill River Pkwy from Exit 27, Marble Ave. to Exit 30, Grand Street were also closed due to flooding. Flooding also closed the Cross County Pkwy. at the Exit 9 ramp to the Hutchinson River Pkwy. |
| September 2008 | Flash Flood | Thornwood | - | The Saw Mill River Pkwy. was closed between exits 25 and 27 in Hawthorne due to flooding. |
| October 2007 | Flash Flood | Thornwood | - | Flash flooding was reported on Saw Mill Parkway in Thornwood and the Hutchinson River Pkwy in Mount Vernon. The Automated Weather Station at Port Chester measured 2.37 inches of rain. |
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 |
|---|---|---|---|
| Sherman Park | 0.3 miles | 40 | |
| Pleasantville | 1.0 miles | 40 | |
| Hawthorne | 1.4 miles | 39 | |
| Graham | 1.6 miles | 39 | |
| Mount Pleasant | 2.0 miles | 39 | |
| Buckhout Corners | 2.2 miles | 40 | |
| Chappaqua | 2.6 miles | 40 | |
| Briarcliff Manor | 2.8 miles | 40 |
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 Thornwood | An encyclopaedic summary. Its text is share-alike, so it is linked here rather than copied. |
| Wikidata item Q3461389 | 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 967439. 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.














