The archived outline of the Alamo Fire spans about 14.1 km from west to east and 15.2 km from south to north. CAL FIRE places the incident at Off Highway 166 near Twitchell Reservoir. The mapped boundary provides a second way to locate the event: it shows the extent around that reference location.
| Start listed by CAL FIRE | 6 July 2017 |
|---|---|
| County listing | San Luis Obispo |
| Reported area in hectares | 11,609 ha (converted from acres) |
| Extent of the mapped outline | 14.1 × 15.2 km (west–east × south–north) |
| Containment entry in the archive | 9 January 2018 |
| Perimeter collection method as recorded | GPS-Flight |
What the perimeter shows
The two spans differ by only 1.0 km. That does not make this a circular burn: the dimensions measure the outermost coordinates, leaving indentations and gaps invisible. Use the polygon itself, rather than its enclosing rectangle, to check whether a location intersects the footprint.
Two estimates of area
The incident report gives 28,687 acres; the interagency feature stores 28,834.1 GIS acres. The mapped value is 147.1 acres above the reported value (0.51%). This compares two published measurements, not two observation times. The difference cannot be read as fire growth.
CAL FIRE also records structures damaged: 1; structures destroyed: 14. Those counts come from the incident record. A building inside the perimeter cannot be assigned a damage category from this map alone.
A similar-sized fire for comparison
The Cedar Fire of 2016 is the closest match by reported acreage in this 100-case collection (29,322 acres). Its mapped spans are 18.4 by 15.6 km, west–east then south–north, versus 14.1 by 15.2 km here. The longer axes run in different directions. Matching on acreage would miss that contrast.
Sources and map method
- Alamo Fire · CAL FIRE incident record
- NIFC interagency history · source perimeter (GeoJSON)
- Cedar Fire · comparison incident
- Comparison perimeter · interagency record
Spans use the geographic extremes of a generalized boundary, converted to kilometres at its middle latitude. They are approximate map dimensions, not distances travelled by flames. The GIS acreage is the source attribute, not an area recalculated from the simplified outline.