Unprecedented: The 2020 Oregon Labor Day Wildfires

The 2020 fire season was another record year for wildfires across the Western United States. Almost 14 million acres were burned, some 18,000 structures were destroyed, and suppression costs amounted to over $3.6 billion. Oregon alone counted for 1.2 million of those acres, 3,000 plus structures, and the most tragic cost of all, eleven lives. In early September five fires on the Western Side of the Cascades exploded due to several contributing factors burning in total almost 850,000 acres in what is referred to as the Oregon Labor Day Fires.

Several key factors contributed to these large fires exploding in size. On a national scale, the majority of the West faced some form of drought, with several areas facing extreme drought. Fire season was also well underway and large fires were burning throughout the West placing strain on fire resources. At the onset of Labor Day weekend fire resources in Region Six (Washington & Oregon) already were at a preparedness level of five, indicating that regionally there were so many major incidents that there was potential to exhaust, or all agency fire resources had been exhausted. This was also the case for fire resources nationally, meaning little to no help was to be expected in the short term.

On the morning of September 7th, 2020 the National Weather Service had issued a Red Flag Warning for potential extreme fire weather throughout the Western Cascades, prompted by an incoming East wind event moving across the Cascades. That evening, just as the winds were truly picking up, at approximately 8:20 a fire was reported East of the town of Blue River, OR. Pushed by winds gusting up to 80 miles per hour, the Holiday Farm Fire (HFF) exploded. In a little over 24 hours, 105,523 acres had been burned and the HFF had ripped through the communities of Blue River and Vida.

With regional trends of drought, extreme fire weather, fuel loading and a number of other variables it is a monumental task to try and disentangle what the main driving factors of the HFF. It is clear in map two that wind was a dominant factor in the blow up, note that after the winds died down on September 9th, growth was relatively minimal compared to the previous day.

Wildfires are inherently complex issues with no clear cut answer as to how we can better prevent or fight them. But natural resource managers can focus in on different components to better understand the issue as a whole. Ownership and land management practices play a significant role in the way a landscape is shaped. Logging practices in Western Oregon vary greatly between public and private land ownership.

Map four highlights different canopy heights before the Holiday Farm Fire within the fire footprint. The patchwork of reds and oranges highlight areas that have recently been clear cut with trees ranging from just over a meter to over three stories high. These patches are extremely homogeneous and create large areas of continuous fuel. When you compare the map of ownership to canopy height you can clearly see that canopy height serves as a proxy to both ownership and management styles. Public land is predominantly populated by trees with canopies greater than 20 meters while private land is a patchwork of clear cuts with few and far between areas of large trees.

Each fire season seems to be worse than the last, and with the current climate crisis that trend is expected to stay. Which leaves the question of what can be done to better adapt to fire prone ecosystems? In recent years its become clear that the past century of full fire suppression has led to multiple problems on both public and private lands. One of those being an over abundance of fuel that has led to massive pest outbreaks and fuel loading that has often turned public and private lands into massive tinderboxes. Critics of federal natural resource managers claim that land management agencies should actively increase logging and grazing to reduce these fuels. Others argue that thinning and reintroduction of prescribed fire is the solution, a long practiced tradition of indigenous people pre-colonization.

Map seven demonstrates vegetative severity for the Holiday Farm Fire. It is important to note that during the wind event of September 8th we see predominantly high severity. We can strongly hypothesize that this is due to the correlation between extreme fire behavior and the extreme fire weather experienced that day. We can direct our attention to two corners of the HFF for important takeaways. By performing a visual analysis on the Northeast and Southeast corners of the HFF we can draw an important conclusion. The NE corner is managed by the USFS with mature mixed canopy height canopies while the SE is private land with the characteristic patchwork of clear-cuts.

By using the above slider tool we can clearly see that in the SE corner where there are a high concentration of clear-cuts there is a disproportionately higher level of severity whereas in the NE, under USFS management, there is a marked difference suggesting how mixed height and or older growth canopies burn at lower severities under normal fire weather conditions.

In this specific example, on this specific fire, it is visually clear that the clear cut logging practices common in the Western Cascades, contribute directly to higher levels of severity during normal fire weather. In response to the mantra log it, graze, or we'll all watch it burn, the story of the Holiday Farm Fire tells us that we can clear cut it and we can all watch it burn hotter.

This and more is covered in depth in a full report by A. Harris, K. Weil, and J. Koffel here: https://static1.squarespace.com/static/5e2c7d5a807d5d13389c0db6/t/60834fbc90c9ed3251ec8907/1619218392073/Labor+Day+Fires+Analysis+%28Harris+et+al.+April+2021%29+FINAL+%281%29.pdf