The Donner Ridge Fire

In August 1960, construction crews burning slash at the new I-80 at Donner Summit touched off a fire that quickly spread up-slope and took off.

The Donner fire blew through Sagehen’s thick, fire-suppressed, second growth forest and masses of leftover slash from the Comstock logging era. The fire ultimately torched a third of the watershed, leaving little still alive. The Donner Ridge Fire, unprecedented at the time, was

merely a preview of the massive wildfires that would become common beginning in the early 2000’s.

Sagehen’s scientists made lemonade, exploring research opportunities in monitoring the return of trees and wildlife over the next 50 years.

Raphael et al., 2014. “Breeding Bird Populations during Fifty Years of Post-Fire Succession in the Sierra Nevada.

Why Did The Fire Burn So Hot?

“When the Sierra Nevada Ecosystem Project (SNEP) team was collecting fire histories and other historical ‘pictures’ of the past conditions, one of the fire group members showed us the detailed USGS topographic survey of that portion of the Sierra done by, I seem to recall, a geologist named Russell in the early 1900s [in Leiberg, 1902(?)]. In addition to the topography and geological features of such a mapping, Russell also mapped the locations and relative quantity of logging slash/debris left behind from the Comstock and later logging. This logging moved, as you know, out of the Tahoe basin into the basins in sequence from Donner Creek, Alder, Prosser, Sagehen, Little Truckee. Russell’s map mentions and showed on his map the extensive and huge quantities of slash and debris in the northward trending band below the crest over to the Little Truckee.

When the SNEP fire team compared his mapped “fuel” deposits with the outlines of the Donner Ridge fire (which they obtained from Forest Service digital files), they found an almost perfect overlay of the boundaries. It was hard not to conclude cause/effect or at least why the fire had such intensity (albeit with the help of a strong north blowing wind and dry conditions) and direction. It was one among many examples that SNEP group used to formulate their conclusions about the important role of past logging  disturbance (both in terms of fuels and forest structure) in creating conditions of extreme fire behavior. And that the “problems” of fire are not just a function of “fire exclusion” of more recent management. The old historical photos from the Hobart Mills  collection are also suggestive. The logs on the trains are relative short but large diameter pines, thus much more was left behind than taken to the mill.

In the early 1970s I led a small number of our Forestry School faculty up to the “Sagehen Pond” cirque lake. I was complaining about the proposed new logging being talked about and wanted some of their impressions. They, all forest harvest supporters, were somewhat stunned by the quantity of large material still on the ground from recent past logging and “clean up”. Entries into virgin timber, they noted, often result in a high percentage of unusable wood because of defect, and so large trunks or pieces were simply left to rot after felling. Such detail is not covered in the final report, I fear, but because of my interest in Sagehen the team knew I would like to know about such a finding.” — D. C. Erman, 2018

It’s important to note that the large fires–like the Donner Ridge Fire and the 1910 “Big Blowup”–began burning before Environmentalism, the EPA and the Endangered Species Act even existed. In fact, US Environmentalism arose as a direct response to forest management practices that led to these mega-fires. Today, it’s popular to blame the Environmentalists for these disastrous fires, suggesting that everything would be fine if we had just let industry continue to treat our public forests as nothing more than tree farms. The evidence suggests otherwise.