Alder Creek Fire
202138,181 acresMontana
The Alder Creek Fire burned 38,181 acres, about 60 square miles, across Beaverhead County. It began on July 8, 2021.
Watch how it happenedAlder Creek Fire · 2021
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 | 20% | 7,670 |
| Moderatemixed: many trees killed, some survive | 21% | 8,075 |
| Lowsurface fire, most trees survive | 45% | 17,281 |
| Unburned to lowislands inside the perimeter, little change | 13% | 5,065 |
| Increased greennessvegetation greener after the fire than before | 0.1% | 21 |
| Not mappedcloud, shadow or water in the satellite images | 0.2% | 68 |
20% of the area inside the perimeter burned at high severity, about 7,670 acres; 41% 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.
| Beaverhead County | MT | 38,185 |
Other large fires in Montana in 2021
- Richard Spring Fire168,686 acres
- P F Fire66,446 acres
- Trail Creek Fire62,475 acres
- Woods Creek Fire55,808 acres
- Thorne Creek Fire39,680 acres
- Harris Mtn Fire31,769 acres
- Robertson Draw Fire31,126 acres
- Haystack Fire26,109 acres
Monitoring Trends in Burn Severity (USGS and U.S. Forest Service). Type recorded: Wildfire.