Largest Wildfires in US History by Acres — and the Biggest in Every Western State (Mapped)

What is the largest wildfire in US history? By the old estimates, either the "Big Burn" of August 1910, when hurricane-force winds fanned some 1,700 fires across about 3 million acres of Idaho and Montana, or the October 1871 Peshtigo fire, which NIFC's fire history puts at 3.78 million acres in Wisconsin and Michigan (NWS: about 1.5 million). Both are estimates, listed separately below. Among fires with an official final size and a mapped perimeter, the largest is Alaska's Kateel River #5 fire of 1957, at 1,161,200 acres. The largest in the lower 48 states is the Smokehouse Creek Fire (Texas Panhandle, February 2024), at 1,054,153 acres in the national incident record (Texas A&M Forest Service's final update gave 1,058,482). Two 2026 fires have since joined the list: Nebraska's Morrill Fire and Oregon's Big Grass Fire, each now its state's record.

How We Rank: Official Acres, Not Satellite Outlines

Fire size is counted three ways, and they disagree:

• Reported final size: the acreage the managing agency records when the fire is out. We rank by this. Sources: the Alaska Interagency Coordination Center (AICC) fire history; the US Forest Service's fire occurrence record (FPA-FOD, 1992–2024); and the interagency WFIGS/IRWIN incident record (2014 onward).
• Mapped perimeter: the GIS area inside the final perimeter, from NIFC's Interagency Fire Perimeter History. For older fires the two can differ widely: the 1950 Little Black River fire was reported at 892,900 acres, but its mapped perimeter encloses 1,366,799.
• Alert or satellite footprint: the outline of a warning, or the area of satellite heat detections. These are not burned area, and we never rank by them.

Complexes, groups of fires managed as one incident, are listed separately. OBSERVED marks a measured or reported fire size, ALERT a product DisasterAWARE issued; loss figures are estimates from the sources cited.

The Largest US Wildfires Since 1950

These are all the single US wildfires since 1950 with a reported final size of 500,000 acres or more in the national incident records (OBSERVED). In those records there are 19, and 11 are in Alaska.

Reported acres: AICC Alaska fire history (Alaska), FPA-FOD 2024 edition (Long Draw, Wallow), WFIGS/IRWIN incident record (2014 onward). Mapped acres: NIFC Interagency Fire Perimeter History and WFIGS perimeters; Starbuck from the MTBS burned-area boundary. State = where the fire started. Big Grass as of 2026-10-09. Before 1992 the national incident record covers only Alaska. The one earlier lower-48 fire known to exceed 500,000 acres is Yellowstone's 1988 North Fork Fire, which started in Idaho's Targhee National Forest and burned 504,025 acres (1988 interagency survey); it is not ranked here.

What stands out:

• Alaska dominates, and its old numbers are rough. Eleven of the 19 are Alaskan, and the reported sizes of the 1950s and 1960s fires are pre-satellite estimates. Hence the gaps between mapped and reported acres for Little Black River, Holanada Creek and Buza; by mapped area, Little Black River would rank first.
• The lower 48's giants are recent. All eight lower-48 fires in the table burned in 2011 or later, and three of them in 2024–2026. Smokehouse Creek, Starbuck and Morrill were Plains grass and rangeland fires.
• The August Complex is not one fire. CAL FIRE's largest California wildfire, the 2020 August Complex (1,032,648 acres), was a group of lightning fires; its largest member, Doe, ranks 10th on its own.

The Largest Fire Complexes

Some complexes merge, others never touch. These are all US complexes of 750,000 acres or more in the national records (OBSERVED, total of all member fires):

1. Taylor Complex, Alaska, 2004: 1,303,356 acres (FPA-FOD, seven fire records).
2. August Complex, California, 2020: 1,032,648 acres (CAL FIRE; WFIGS).
3. East Amarillo Complex, Texas, 2006: 907,245 acres (FPA-FOD, two fire records).
4. Lime Complex, Alaska, 2022: 865,625 acres (WFIGS).
5. Solstice Complex, Alaska, 2004: 812,765 acres (FPA-FOD, 19 fire records).
6. NW Oklahoma Complex, Oklahoma and Kansas, 2017: 779,292 acres, including Starbuck (WFIGS).

FPA-FOD covers 1992–2024 and WFIGS 2014 onward; complexes before 1992 are not in either record.

Before the Perimeter Era: The Great Fires of 1871–1941

Sizes of these pre-perimeter fires are estimates that vary widely by source, so they are listed by date, not ranked.

• Peshtigo Fire, Wisconsin, October 8, 1871: about 1.5 million acres (NWS) to 3.78 million with the Michigan fires (NIFC); an estimated 1,200–2,400 deaths.
• Thumb Fire, Michigan, September 4–6, 1881: well over 1 million acres; 282 deaths (MSU; NIFC: 169).
• Great Hinckley Fire, Minnesota, September 1, 1894: 350,000 acres; at least 418 deaths.
• Yacolt Burn, Washington, September 1902: nearly 239,000 acres; 38 deaths.
• Big Burn (Great Fire of 1910), Idaho and Montana, August 1910: about 3 million acres; about 85 deaths.
• Cloquet–Moose Lake fires, Minnesota, October 12, 1918: from 250,000 acres (NWS) to 1,500 square miles (MNopedia); over 450 deaths.
• Ruby fire, Alaska, 1940: 1,250,000 acres (AICC estimate).
• Unalakleet fire, Alaska, 1941: 1,000,000 acres (AICC estimate).

Sources: NWS Green Bay (Peshtigo); Michigan State University (Thumb); Minnesota DNR (Hinckley); Washington DNR (Yacolt); NWCG staff-ride library and Forest History Society (1910); NIFC fire history (Peshtigo, Thumb); NWS Duluth and MNopedia (1918); AICC fire history (Ruby, Unalakleet).

The Big Burn is usually called the largest wildfire in US history, but it was some 1,736 fires, started by lightning and by people, that hurricane-force winds fanned into one blowup on August 20–21, 1910. It killed an estimated 85 people, firefighters and residents, and it shaped Forest Service fire policy for decades. Peshtigo burned the same night as the Great Chicago Fire and remains the deadliest wildfire in American history. Alaska's Ruby fire of 1940 is the largest in AICC's records but predates mapped perimeters.

Map: The Largest US Wildfires and Every State Record

The map shows the 19 ranked fires' final perimeters (Alaska's 1950s ones redrawn later), each state record's origin and, in violet, the 15 deadliest and most destructive fires named below (outlines where agencies mapped them, approximate markers for the oldest).

Open map full screen ↗

Explore the map: more layers are switched off when it opens. Turn them on with the layers icon at the bottom right of the map: fire growth, dated perimeters for 9 fires since 2004; satellite fire detections (NASA FIRMS) and burn severity (MTBS), 2004–2024; smoke and NWS red flag warnings on each fire's key days (2009–2026); and CAL FIRE damage inspections, 45,326 damaged or destroyed structures at Dixie, August Complex, Camp, Tubbs, Eaton and Palisades.

The Largest Wildfire in Each Western State

Each row is the largest fire in that state's own record, by reported final size (OBSERVED), listed under the state where it started.

Acres: AICC (Alaska), FPA-FOD 1992–2024 (Wallow, Murphy, Holloway, Milford Flat), CAL FIRE and WFIGS (August Complex), WFIGS/IRWIN incident record (all others). Clover-Mist: NIFC perimeter history (mapped). Holloway: Central Nevada Interagency Dispatch Center 2012 annual report (215,541 acres in Nevada, 245,547 in Oregon).

Nebraska also has a fire on the national list: the Morrill Fire of March 2026, which burned 642,029 acres of western Nebraska rangeland. Nebraska's governor said its cause was "electrical in nature with wind popping wires and sparks."

The Deadliest US Wildfires

Acreage and deaths rank different fires.

1. Peshtigo, Wisconsin, 1871: an estimated 1,200–2,400.
2. Cloquet–Moose Lake, Minnesota, 1918: over 450.
3. Great Hinckley Fire, Minnesota, 1894: at least 418.
4. Thumb Fire, Michigan, 1881: 282.
5. Lahaina, Hawaii, 2023: 102.
6. Big Burn, Idaho and Montana, 1910: about 85; and the Camp Fire, California, 2018: 85.

The October 1871 Michigan fires, on the same days as Peshtigo, likely killed more than 500 in all (NWS), across several separate fires. Sources: NWS Green Bay; MNopedia (NWS Duluth cites about 1,000 for 1918); Minnesota DNR; Michigan State University; Maui County via the Associated Press (Lahaina); NWCG; CAL FIRE.

Lahaina is the deadliest US wildfire in more than a century, and the Camp Fire is the deadliest in California's records. Next in CAL FIRE's table come Griffith Park (1933, 29 deaths), the Tunnel Fire in the Oakland Hills (1991, 25) and Tubbs (2017, 22). The January 2025 Los Angeles fires killed 19 in the Eaton Fire and 12 in the Palisades Fire.

The Most Destructive US Wildfires

Measured by structures destroyed, these are the six most destructive wildfires in California's records (OBSERVED, CAL FIRE); the top five also lead the national list:

1. Camp Fire (2018): 18,804 structures, on 153,336 acres.
2. Eaton Fire (2025): 9,413 structures, on 14,021 acres.
3. Palisades Fire (2025): 6,833 structures, on 23,707 acres.
4. Tubbs Fire (2017): 5,636 structures, on 36,807 acres.
5. Tunnel Fire, Oakland Hills (1991): 2,900 structures, on 1,600 acres.
6. Cedar Fire (2003): 2,820 structures, on 273,246 acres.

Outside California, the most destructive are the Chimney Tops 2 fire at Gatlinburg, Tennessee (2016; 2,545 structures lost with the fires it merged into), Oregon's Almeda Drive Fire (2020; 2,428 structures destroyed and 134 damaged, per the Ashland Police and Jackson County Sheriff) and Lahaina (2023; about 2,200 damaged or destroyed). None of the six burned even 300,000 acres.

In the DisasterAWARE Archive

The DisasterAWARE historical hazard archive holds 130,061 wildfire records worldwide (pulled October 9, 2026). The archive is alert-grain, so one fire can have many records. Records matched to a fire carry a fire assessment linked to the incident record by IRWIN identifier: final acres, perimeters joined, cause, discovery and containment times. Backfill records were added later from NIFC history, not issued at the time; we count them separately.

Fires here with DisasterAWARE products issued as they burned (ALERT tier; times UTC):

Source: DisasterAWARE Historical Hazards API, queried 2026-10-09; discovery times from the WFIGS incident record.

A few things the archive shows:

• Incident discovery times can be wrong. Morrill's incident record puts discovery 14 hours after DisasterAWARE's first product, though the fire started on March 12, local time.
• Alert-grain means duplicates. The August Complex has two live warnings (the Doe and Hull fires) and 15 backfill records for its member fires and zones.
• Backfill fills the gaps. Starbuck, Carlton and Tubbs are in the archive only as backfill from NIFC history. Starbuck's backfill record carries an early 150,000-acre incident report, and a separate 400,000-acre Kansas grassfire report covers the same days nearby. Even the national incident record holds partial reports, so we rank from each fire's final record (662,700 acres for Starbuck).

The archive also holds live products for Lahaina (a response-support product on August 9, 2023), Hermits Peak–Calf Canyon (filed under Calf Canyon), the Lime Complex's Koktuli River fire, Remington, House Draw, Cameron Peak, Bootleg, Mullen, Martin, Lodgepole, Woolsey, Marshall and Chimney Tops 2. It cannot yet tell an incident confirmed by NIFC from a satellite detection that may not be a fire, so we do not publish archive fire counts.

For Insurers and Reinsurers: Acres Don't Drive Loss

The largest fires on this page burned tundra, sagebrush and grassland; the costliest burned neighborhoods. Wildfire loss is a question of exposure in the wildland–urban interface (WUI) and, increasingly, of who started the fire.

• Los Angeles, January 2025. The Palisades Fire burned 23,707 acres and the Eaton Fire 14,021 (CAL FIRE): together less than 4% of Smokehouse Creek's area. Munich Re puts the overall loss at around US$53 billion, about US$40 billion of it insured: the most expensive wildfire disaster to date.
• Camp Fire, 2018. On 153,336 acres, it destroyed 18,804 structures and killed 85 people. Munich Re puts the overall loss at US$16.5 billion, US$12.5 billion insured: the costliest natural catastrophe of 2018 worldwide.
• Tubbs and the 2017 fires. Tubbs burned 36,807 acres in Napa and Sonoma counties and destroyed 5,636 structures. California's Department of Insurance counted more than US$11.79 billion in insured losses from the October and December 2017 wildfires, Tubbs among them.

Utility liability. The ignition source now shapes recovery and subrogation:

• Camp. PG&E pleaded guilty to 84 counts of involuntary manslaughter. Its bankruptcy plan put US$13.5 billion into the Fire Victim Trust, which covers the Camp Fire, the 2017 North Bay fires (Tubbs among them) and the 2015 Butte Fire.
• Dixie. CAL FIRE lists its cause as power lines.
• Lahaina. A US$4.037 billion global settlement (Maui County) resolved the 2023 Maui fire claims; Hawaiian Electric's share was US$1.99 billion, with no admission of liability.
• Smokehouse Creek. Xcel Energy acknowledged that its facilities "appear to have been involved in an ignition" of the fire, while disputing negligence.
• Eaton. The US Department of Justice sued Southern California Edison in September 2025, alleging that its equipment ignited the fire.
• Tubbs. CAL FIRE found a private electrical system, not PG&E, caused it.

The data question. Underwriting and subrogation need event-level facts: origin, perimeter growth and cause. DisasterAWARE's wildfire data links each fire's alerts to its perimeters, final acres, cause, discovery and containment times. Smokehouse Creek alone has 34 perimeters joined and Dixie 656. Historical Event Intelligence licenses the archive across every hazard, and the sample datasets show the record format with no signup.

Frequently Asked Questions

What is the largest wildfire in US history? By the old estimates, the 1910 Big Burn (about 3 million acres in Idaho and Montana) or the 1871 Peshtigo fire (3.78 million acres in NIFC's history; 1.5 million by NWS). Among fires with an official final size and a mapped perimeter, it is Alaska's Kateel River #5 fire of 1957 (1,161,200 acres). In the lower 48 it is Texas's 2024 Smokehouse Creek Fire (1,054,153 acres).

What is the largest wildfire in California history? The August Complex of 2020, a group of lightning fires, at 1,032,648 acres (CAL FIRE). The largest single fire is the 2021 Dixie Fire, at 963,309 acres.

What is the deadliest wildfire in modern US history? The Lahaina fire on Maui, on August 8, 2023, which killed 102 people. The deadliest in American history is the 1871 Peshtigo fire in Wisconsin, with an estimated 1,200 to 2,400 deaths.

What is the costliest wildfire in US history? The January 2025 Los Angeles fires, Palisades and Eaton: around US$53 billion overall and about US$40 billion insured, by Munich Re's estimate, the most expensive wildfire disaster to date.

What is the largest wildfire in Colorado history? The Cameron Peak Fire of 2020, at 208,913 acres, ahead of the 2020 East Troublesome Fire (193,812 acres).

Related Reading

• Wildfire Data: Perimeters, Final Acres and Cause for Every Fire
• Reconstructing Historic Wildfires
• Satellite Fire Detections vs Wildfire Intelligence
• Secondary Perils and Insurance Risk
• Wildfire Risk in Los Angeles, CA

Sources: AICC Alaska fire history; USDA Forest Service FPA-FOD (1992–2024); NIFC WFIGS and Interagency Fire Perimeter History; USFS/USGS MTBS; CAL FIRE top-20 lists; Ashland Police Department and Jackson County Sheriff (Almeda Drive, 2022); Texas A&M Forest Service; NWS Green Bay, NWS Duluth; NWCG; Minnesota DNR; MNopedia; Washington DNR; Michigan State University; Forest History Society; NIFC historically significant fires; Central Nevada Interagency Dispatch Center (Holloway); Munich Re; California Department of Insurance; US Department of Justice; Hawaiian Electric; Maui County; Fire Victim Trust; Pacific Disaster Center/FEMA (Lahaina structures); NPS Chimney Tops 2 fire review (Sevier County data); 1988 Greater Yellowstone interagency survey (North Fork); Xcel Energy; Associated Press; Nebraska Public Media; DisasterAWARE Historical Hazards API (queried 2026-10-09).