Study: Tree Thinning Didn’t Slow ’10 Boulder, Colo., Fire

A study of a devastating Colorado wildfire says advance work to create fire breaks had little impact on the behavior of the blaze but did provide safe transpiration routes.

The 2010 Fourmile Canyon Fire west of Boulder was the most destructive in Colorado history, destroying 168 homes and causing $217 million in insurance losses.

A research team studied the fire and released a draft report Friday. Democratic Sen. Mark Udall requested the review.

Trees had been thinned on 10 percent of the 9-square-mile burn area before the fire, much of that along roads, in hopes of creating breaks to stop or slow a wildfire.

The research team leader, Russell Graham of the Rocky Mountain Research Station, says thinning was ineffective because it left too much flammable material on the ground.