Richard White’s history of the extension of railroads across the western United States (Railroaded: The Transcontinentals and the Making of Modern America – great read) has fascinating excerpts from the 1870 diary of H.K. Thomas, the Union Pacific stationmaster in Laramie, Wyoming. The normal fires of summer in the mountains are mentioned twice – “covering the valley in a thick, smoky haze.”

In working over the past month on a newspaper piece about forest health and fire danger here, several people I interviewed talked about the central importance of getting us accustomed to smoke, so it seems normal, as it was in Thomas’s day. Why? Because fire really is a part of these systems, and its reintroduction is critical in the long run to getting forests healthy again and avoiding catastrophic, ecosystem-changing blazes.

From the Sunday Journal (sub/ad req):

Scientists say that before we started fighting fires, the woods here burned every three to 25 years, depending on location and forest type. Some fires hugged the ground, clearing needles and small trees and leaving large, fire-hardened trees to survive. Some fires were patchy, destroying one clump of trees and leaving others nearby intact.

In dry years, fire would sometimes roam across the landscape for months at a time, burning millions of acres, far more than we see today, Falk said. But it would burn lightly, leaving behind healthy open stands of forest.

Fire was a natural part of that system, he said. “Fire is something forest ecosystems do. It’s not something that happens to them.”

Putting out fires allows fuel to eventually build up to unsupportable levels. In addition, smaller trees create a pathway for fire to climb up into the tops of trees, which forecasters call a “fuel ladder,” allowing fire to take off. Something has to give.