Btt S 17 Fire
199143,568 acresAlaska
The Btt S 17 Fire burned 43,568 acres, about 68 square miles, across Yukon-Koyukuk Census Area. It began on June 30, 1991.
Watch how it happenedBtt S 17 Fire · 1991
How it happened
See how severely each place burned, revealed outward from where it started.
How severely it burned
Burn severity inside the final perimeter, classified from Landsat images taken before and after the fire.
| Severity | Share | Acres |
|---|---|---|
| Highmost vegetation consumed, soils altered | 13% | 5,565 |
| Moderatemixed: many trees killed, some survive | 54% | 23,441 |
| Lowsurface fire, most trees survive | 19% | 8,206 |
| Unburned to lowislands inside the perimeter, little change | 4.2% | 1,811 |
| Increased greennessvegetation greener after the fire than before | 0.1% | 35 |
| Not mappedcloud, shadow or water in the satellite images | 10% | 4,510 |
13% of the area inside the perimeter burned at high severity, about 5,565 acres; 67% 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.
| Yukon-Koyukuk Census Area | AK | 43,559 |
Other large fires in Alaska in 1991
- Yukon Flats 26 Fire122,822 acres
- 131569 Fire109,499 acres
- Btt W 64 Fire35,602 acres
- 131655 Fire30,237 acres
- Hsl Nnw 37 Fire27,142 acres
Monitoring Trends in Burn Severity (USGS and U.S. Forest Service). Type recorded: Wildfire.