Observation Fire
200167,493 acresCalifornia
The Observation Fire burned 67,493 acres, about 105 square miles, across Lassen County. It began on August 9, 2001.
Watch how it happenedObservation Fire · 2001
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 | 8.5% | 5,762 |
| Moderatemixed: many trees killed, some survive | 37% | 25,178 |
| Lowsurface fire, most trees survive | 40% | 27,000 |
| Unburned to lowislands inside the perimeter, little change | 14% | 9,546 |
9% of the area inside the perimeter burned at high severity, about 5,762 acres; 46% 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.
| Lassen County | CA | 67,432 |
Other large fires in California in 2001
- Blue Complex (Blue)30,817 acres
- Trough Fire25,249 acres
Monitoring Trends in Burn Severity (USGS and U.S. Forest Service). Type recorded: Wildfire.