131569 Fire

1991109,499 acresAlaska

The 131569 Fire burned 109,499 acres, about 171 square miles, across Yukon-Koyukuk Census Area. It began on June 30, 1991.

Watch how it happened

131569 Fire · 1991

How it happened

See how severely each place burned, revealed outward from where it started.

About this replay
IgnitionJune 30, 1991Historical replay — order not recorded
Final area109,499 ac
Revealed—
Counties1

How severely it burned

Burn severity inside the final perimeter, classified from Landsat images taken before and after the fire.

Map of burn severity across the 131569 Fire
Burn severity by class
SeverityShareAcres
Highmost vegetation consumed, soils altered35%37,957
Moderatemixed: many trees killed, some survive43%47,538
Lowsurface fire, most trees survive15%16,335
Unburned to lowislands inside the perimeter, little change5.3%5,803
Increased greennessvegetation greener after the fire than before0.7%738
Not mappedcloud, shadow or water in the satellite images1.0%1,128

35% of the area inside the perimeter burned at high severity, about 37,957 acres; 78% burned at moderate or high severity.

Monitoring Trends in Burn Severity (U.S. Geological Survey and USDA Forest Service). Classes come from the change in a Landsat burn index (dNBR) between images before and after the fire; acres are each class’s share of the fire’s mapped area.

Where it burned

Acres inside each county, measured from the satellite-mapped perimeter.

Acres burned by county
Yukon-Koyukuk Census AreaAK109,445

Other large fires in Alaska in 1991

Monitoring Trends in Burn Severity (USGS and U.S. Forest Service). Type recorded: Wildfire.