Helmet Fire
201735,919 acresAlaska
The Helmet Fire burned 35,919 acres, about 56 square miles, across Yukon-Koyukuk Census Area. It began on July 6, 2017.
Watch how it happenedHelmet Fire · 2017
How it happened
Watch it burn in the order satellites saw it, coloured by how severely each place burned.
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 | 29% | 10,257 |
| Moderatemixed: many trees killed, some survive | 42% | 15,107 |
| Lowsurface fire, most trees survive | 20% | 7,203 |
| Unburned to lowislands inside the perimeter, little change | 9.2% | 3,301 |
| Not mappedcloud, shadow or water in the satellite images | 0.1% | 49 |
29% of the area inside the perimeter burned at high severity, about 10,257 acres; 71% 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 | 35,939 |
Other large fires in Alaska in 2017
- Campbell River Fire161,363 acres
- White Mountain Creek Fire97,960 acres
- Nowitna Fire53,691 acres
- Bear Mountain Fire48,058 acres
- Boulder Creek Fire40,369 acres
- Lois Creek Fire33,996 acres
Monitoring Trends in Burn Severity (USGS and U.S. Forest Service). Type recorded: Wildfire.