For the next four and a half months, the sounds of feller bunchers, processors and lumber trucks will be a common one around the lower Dry Lake Hills and the base of Mount Elden.

This week, loggers are getting into full swing on the thinning of 642 acres of forest north of Flagstaff as part of the Flagstaff Watershed Restoration Project, or FWPP. The deadline for those acres to be completed is the end of the year.

The work is part of the first phase of the fuels reduction project, which uses hand and mechanical thinning as well as prescribed fire in the Rio de Flag and Lake Mary watersheds. The work aims to mitigate the risk of severe fires and destructive post-fire flooding around Flagstaff’s key water sources. A $10 million bond to support the project was approved by the city's voters in 2012. 

Here’s what you need to know about current work:

Where the work is happening: For the next month or so, the logging contractor will be mechanically thinning in an area east of Elden Lookout Road and north of the Pipeline Trail, near the intersection of the Rocky Ridge Trail and the Lower Oldham Trail, said Sean Murphy, an environmental protection specialist on the Coconino National Forest.

Thinning The Watershed

Mike Elson, Flagstaff District Ranger, looks over a section of forest being thinned as part of the Flagstaff Watershed Protection Project Monday morning. Mechanical thinning began this week in the Dry Lake Hills area, requiring several trail closures. 

Trail closures: Trails that will be closed during this segment of work include the Lower Oldham and Rocky Ridge trails. The Arizona Trail will be re-routed through the city. Signs warning of area closures and the presence of logging activity are posted on trails and roads. The closures are enforced at all times — not just when work is going on — because the logging creates hazards in the forest that aren’t immediately cleaned up, said FWPP Coordinator Jessica Richardson.

Trail closures will change as work progresses and that information will be updated on the FWPP and Coconino National Forest websites, Richardson said.

Closed For Thinning

A mountain biker rides out of a closed road Tuesday morning in a section of forest being mechanically thinned as part of the Flagstaff Watershed Protection Project, or FWPP. The Forest Service's timber sale administrator said he has seen and heard of dozens of people ignoring trail closures necessitated by the presence of heavy logging equipment in the forest. 

In the first few days of thinning, dozens of people have been ignoring the Forest Service's closure signs, with some coming within 50 feet of operating logging equipment, which is a definite danger zone, said Ryan Harlow, the Forest Service’s timber sale administrator for this project.

A high school cross country team even ran through the area on Monday, according to the logging contractor, Harlow said.

Local bike shops say the trail closures haven’t been a problem when it comes to recommending places for people to ride around Flagstaff.

“There are plenty of trails in other places,” said Anthony Quintile, general manager at Absolute Bikes. Most people understand that the FWPP fuels reduction will help save the trails in the long run, Quintile said.

Trail and road impacts: The logging contractor is constructing temporary roads through the forest that will be used to haul logs out to main transport routes. Forest Service system trails that were converted to temporary logging roads or were otherwise impacted by logging activity will be rehabbed once work is finished, said Mike Elson, the Flagstaff District ranger. The same won’t be done for non-system trails though, because the Forest Service doesn’t have the responsibility to maintain them, Elson said.

Flagstaff Watershed Protection Project

Felled trees lie waiting to be processed in an area of forest in the Dry Lake Hills being thinned as part of the Flagstaff Watershed Protection Project. Mechanical thinning in the area began this week, necessitating several trail closures and reroutes. 

What’s happening with the trees: In the areas of ponderosa pine that are being thinned, tree densities will be reduced from an average of 314 trees per acre to 138 trees per acre, according to a silviculture analysis. The harvested logs will be going to a pallet mill in Phoenix and to the Lumberjack Mill in Heber operated by New Life Forest Products, formerly Good Earth Power AZ, which is the holder of the largest thinning contract on the 2.4 million-acre Four Forest Restoration Initiative.

The forest slash will be piled to dry and then will be burned by Forest Service crews when weather conditions are appropriate.

At the height of work, the contractor expects to haul eight to 10 loads of logs per day out of the forest, Harlow said.

Trees to cut, trees to keep: In the current phase of the fuels reduction work, which mostly involves ponderosa pine forest outside of Mexican spotted owl habitat, there is no maximum diameter above which trees cannot be harvested. However, tree cutting prescriptions on the project generally require loggers to retain the oldest, largest trees, including the yellow pines, Elson said. Those trees may be cut, however, if they are diseased, are posing a hazard or need to be removed for the creation of a road or temporary landing to store cut trees, he said.

Watershed Protection

Orange marker paint indicate trees not to be cut in a section of forest being thinned as part of the Flagstaff Watershed Protection Project near Elden Lookout Road. 

There are many different colors of flagging tape tied to tree branches in the logging area, but Richardson said residents only need to pay attention to the colors painted on trees.

Blue means trees to be cut and orange means trees to be left. The orange paint is supposed to fade in two to five years, Richardson and Elson said.

Emery Cowan can be reached at (928) 556-2250 or


Emery Cowan writes about science, health and the environment for the Arizona Daily Sun, covering everything from forest restoration to endangered species recovery efforts.

Load comments