A crew of 5 ACE sawyers just returned from a project removing 2 miles of hazard tress which posed a risk to ski trails around the Pajarito Mountain Ski Area in New Mexico. This area had been affected by the 2011 Las Conchas Fire which burned 150,000 acres and threatened the Los Alamos National Laboratory and the nearby town of Los Alamos. After five days of burning it became the largest wildfire in New Mexico’s history, although this record was broken in 2012 and the Whitewater-Baldy Complex Fire.


So what makes a tree a ‘hazard tree’? The US Forest Service describes a hazard tree as ‘…a tree with structural defects likely to cause failure of all or part of the tree…” Effectively, hazard trees are dead but remain standing. They pose a danger to the public as they can fall without warning. It is therefore important to remove them from the vicinity of the trail, or ski run, to ensure the safety of the public.


ACE sawyers are selected for Hazard Tree Felling based upon several criteria: Positive feedback from project partners and ACE Crew Leaders, demonstrating that they are interested and capable of progressing their saw skills, and, most importantly, having ample experience with the saw so that they can complete hazard tree cutting techniques safely and efficiently.


The hazard tree training includes a review of different tree species that they may find, tree fiber structures and their effects on the felling of a tree, how to size up a complex tree, advanced cutting techniques and cuts, cut selection, and advanced wedging techniques. It’s also important the sawyers know a ‘walk away situation’ – a tree that cannot be safely felled at that time.


At the Pajarito Mountain Ski Area the ACE sawyers felled a total of 109 hazard trees over 9 days, helping to secure the area in advance of the 2015 ski season.

Hazard Tree Crew

Hazard Tree Crew

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