Wildfire evidence study · California, United States · 2017
How large was the Nuns Fire? A responsible answer must first define which merged fires the name includes. The operational archive and the later investigation grouping show different acreages. Treating those labels as perfectly equivalent creates an apparent contradiction that cannot be resolved by choosing the larger number.
Documentary review · Sources checked 30 October 2026 · Historical case, not live incident information.
The published event record
| Field | Recorded value |
|---|---|
| Start | Night of 8 October 2017 (investigation account) |
| Later milestone | Merged-event record; no single closing date used |
| Reported acres | 44,573 archive entry; 56,556 merged investigation group |
The 2017 archive lists a Nuns/Adobe/Norrbom/Pressley/Partrick/Oakmont entry at 44,573 acres. CAL FIRE’s June 2018 statement reproduced in a PG&E filing describes Norrbom, Adobe, Partrick, Pythian and Nuns as a series that merged, reporting 56,556 combined acres. It attributes the Nuns ignition to a broken treetop contacting a power line. These are differently labeled group records. See primary records below.
A complex needs an explicit membership list
Before combining a dataset, create an event-to-component crosswalk. Each component needs its own name, identifier where available, and membership dates. A complex total must not be added to the totals of its constituent fires as though they were independent burned areas.
A simple numerical subtraction between 56,556 and 44,573 would be arithmetically possible, but it would not establish additional fire growth. The difference could involve scope, mapping or record revision. The sources reviewed here do not isolate those contributions, so this study does not label the difference as newly burned land.
Cause information requires the same discipline. The finding for Nuns does not automatically describe every component in the merged group. Different ignition events can later produce one connected burned footprint. One final polygon therefore cannot be assumed to mean one initial cause.
For regional comparisons, use a consistent unit: either the merged event or the component incidents, with spatial overlap handled explicitly. This article counts the merged case once in Tecnobosque’s archive. It does not create separate case-count entries for every name in the same group.
What this study does and does not establish
No GIS union, perimeter reconciliation or new acreage estimate was performed. The two values are retained with their source scope. Exact equivalence between the group definitions remains unresolved.
This is a documentary evidence review, not fieldwork or an independent forensic investigation. Published numbers retain their source definitions. Differences are identified rather than silently reconciled. The analysis above is Tecnobosque’s interpretation of the cited record.
Primary records and source notes
- Nuns and Merged Fires: official incident or annual record — chronology, scope and reported figures discussed above.
- PG&E filing reproducing CAL FIRE findings for the merged fires — used only for the findings explicitly attributed in this study.
Continue the investigation
Mendocino Complex: Ranch, River and event scope · Read our evidence-review method · Browse United States cases · Browse the full fire archive
Cite this record
Tecnobosque. “Nuns Fire 2017: Merged Incidents, Acreage Differences and Double Counting.” Documentary evidence review, 30 October 2026. https://tecnobosque.com/nuns-fire-2017/. Cite the underlying primary source when reusing its figures.