Colorado Wildfire, Measured: Seven Fires Over 100,000 Acres, Five of Them Since 2020

Part one of three. Part two is about when Colorado burns; part three is about where FEMA has been called.

The National Interagency Fire Center keeps two public records of where fires burned: a historical archive of mapped perimeters from 1984 to 2019, and the current interagency perimeter service from 2020 on. Together they hold 2,329 Colorado fires and 3,586,556 acres. This post reads that record as it stands. It does not model anything.

One housekeeping note, because it changes the totals. The historical archive lists some fires twice, under the same name in different capitalization: High Park in 2012 appears as both High Park and HIGH PARK, Missionary Ridge in 2002 likewise. We count each fire once, keeping its larger mapped acreage. That removes 27 duplicate entries and about 208,000 acres that a straight sum would have counted twice.

Seven fires over 100,000 acres

Fire	Year	Acres
Cameron Peak	2020	208,913
East Troublesome	2020	188,915
Pine Gulch	2020	138,846
Hayman	2002	137,760
Lee	2025	137,758
Spring Creek	2018	108,131
Aspen Acres	2026	102,003

For eighteen years Hayman was the largest fire in the record. In the summer and fall of 2020 three fires passed it in a single season. Since then two more have crossed 100,000 acres. Before 2000 the record holds no fire of that size at all; the largest of the 1980s and 1990s, I Do in 1988, mapped 15,067 acres.

A few fires carry most of the acreage

The ten largest fires account for 34.7% of every acre burned in Colorado since 1984. The largest 25, about 1% of all fires, account for 51.3%. Most fires are small: more than half of the record is under 100 acres. A season's acreage is decided by whether one of the few large fires happens, which is why one year can double the decade's total and the next can be quiet.

By period

Period	Fires mapped	Acres	Over 10,000 acres	Over 100,000 acres
1984–1989	118	91,902	1	0
1990s	185	156,424	4	0
2000s	604	849,011	18	1
2010s	665	1,145,536	27	1
2020–2026	757	1,343,682	17	5

The 2020s are not yet seven years old and have already burned more than any full decade before them.

What the record cannot tell you

Fire counts across the 2019–2020 seam are not comparable. The current service maps many more small fires than the historical archive did, so the jump in fires mapped after 2020 is partly a change in what gets recorded. Acreage of large fires is far less sensitive to that: a 100,000-acre fire was mapped in either system.

Early years undercount. Perimeter mapping in the 1980s was sparser than it is now. Treat the earliest decade as a floor.

Acres are not damage. East Troublesome burned 188,915 acres and destroyed 555 structures; the Marshall Fire burned 6,080 acres of grassland and suburb and cost more than every other Colorado wildfire in the NOAA record combined. Part two looks at that difference.

This is the record, not a forecast. Nothing here says what the next decade will bring. It says what happened, from the federal sources, counted once.

See it for your county

Each Colorado county has a page built from the same federal records: Larimer, Grand, Jefferson, Boulder and every other county.

Sources: National Interagency Fire Center, InterAgency Fire Perimeter History and WFIGS Interagency Perimeters (public domain), as loaded into Calchis and queried October 6, 2026; fires counted once by name and year. NOAA National Centers for Environmental Information, Storm Events Database, for the East Troublesome structure count.