Stone Fire (2018): mapping the 39,387-acre footprint

The archived outline of the Stone Fire spans about 19.2 km from west to east and 16.2 km from south to north. CAL FIRE places the incident at Big Canyon, 10 miles SW of Canby. The mapped boundary provides a second way to locate the event: it shows the extent around that reference location.

Start listed by CAL FIRE15 August 2018
County listingModoc
Reported area in hectares15,939 ha (converted from acres)
Extent of the mapped outline19.2 × 16.2 km (west–east × south–north)
Containment entry in the archive4 January 2019
Perimeter collection method as recordedMixed Methods
Stone Fire historical perimeter; north up. Approximate spans 19.2 by 16.2 kilometres.
Generalized historical perimeter. Source: NIFC interagency fire perimeter history.

What the perimeter shows

The two spans differ by only 3.0 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 39,387 acres; the interagency feature stores 39,391.7 GIS acres. The mapped value is 4.7 acres above the reported value (0.01%). This compares two published measurements, not two observation times. The difference cannot be read as fire growth.

A similar-sized fire for comparison

The Bald Fire of 2014 is the closest match by reported acreage in this 100-case collection (39,736 acres). Its mapped spans are 15.0 by 18.2 km, west–east then south–north, versus 19.2 by 16.2 km here. The longer axes run in different directions. Matching on acreage would miss that contrast.

Sources and map method

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.