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Hazard Tree – Identification

hazard-tree-identification-graphic.pngSome common tree deficiencies which contribute to potential felling hazards:

Weak Limbs: limbs of all sizes and species with decay evident cracking, loose, hung-up, or fire damaged limbs. Avoid working under overhead hazards.

Weak Tops: split/schoolmarm tops that could have weakened unions, fire weakened tops, rotten or dead tops.

Witches Broom: caused by mistletoe infection, limbs can grow very large and heavy (200+ lbs). Can contribute to uneven weight distribution.

Split Trunk: cracked trunk from frost, lightning, or wind. Visible evidence of advanced decay indicates serious weakness where the tree could fail. May increase wood fiber tension contributing to barber chair potential.

Stem Damage: caused by windfall, scarring, fire, machine, and animal damage, as well as heart rot diseases.

Cat Face:  look for enough solid wood to construct an effective undercut and back cut. Complexity increases when desired felling direction is different than that of the cat face.

Thick Sloughing Bark: usually found on dead trees. Loose bark, particularly on Douglas firs, can injure sawyers.

Butt and Stem Cankers: usually found on deciduous trees but can occur on Douglas fir and pine. The infected areas weaken the stem.

Fungal Fruiting Bodies or Conks: found on stems may indicate massive interior rot. Excessive resinosis (resin flow) also indicates heart or root diseases.

Heavy Tree Lean: look for any ground cracks around the base of the tree. May be caused by damaged roots or lifting root mats, shallow or wet soils. In some cases, the tree may have corrected itself which can be determined by looking for corrected top growth.

Root Condition: weakened roots may reduce felling control. Signs of decay or fungal conks on the roots, or fire weakened roots.

Species Consideration: consult local experts for species deficiencies particular to local areas. A good habit is to observe overall tree stand health wherever you’re working.

Felling a hazard tree requires accurate risk assessment and complexity analysis and demands the sawyer’s full situational awareness. Do not bypass hazard trees without taking some action such as felling or establishing a No-Work-Zone.

Discuss indicators of tree defects specific to your local area.

 

Category
Felling Safety
References
Hazard Tree Identification Field Guide

6MFS Suggestion Form


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NEW! Incident Performance and Training Modernization Story Map Now Available

Date: Aug 26, 2025
Questions? Please contact:
National Wildfire Coordinating Group

NWCG is excited to announce the launch of the Incident Performance and Training Modernization (IPTM) Story Map, a new interactive resource that showcases how NWCG is transforming wildland fire training and qualifications through a performance-based system.

Since its launch in 2023, IPTM has made major strides in updating how we manage incident positions:

  • 36 incident positions now have new Incident Position Standards and Next Generation Position Task Books available for field use
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The Story Map guides you through the IPTM process, highlights key accomplishments, and outlines what’s ahead. Whether you are a trainer or a trainee, this tool offers valuable insight into the modernization effort shaping the future of wildland fire training and qualifications.

This effort would not be possible without the contributions of NWCG staff, NWCG committees, and hundreds of subject matter experts across the wildland fire community.

References:

IPTM Story Map

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NEW! S-290, Intermediate Wildland Fire Behavior (Blended) Available Now

Date: Aug 15, 2025
Questions? Please contact:
Fire Behavior Subcommittee

NWCG is excited to announce that the S-290, Intermediate Wildland Fire Behavior (Blended) training is now available on the Wildland Fire Learning Portal. S-290 (Blended) training combines online training and instructor-led training components that support individuals working towards any Single Resource Boss or Fire Effects Monitor incident qualifications.

This second course in the series collectively serves to develop fire behavior prediction knowledge and skills, and provides more detailed information on fuels, weather, and topography that affect wildland fire behavior for safety purposes.

Students are required to finish the prerequisite S-190, Introduction to Wildland Fire Behavior, before enrolling in S-290, Intermediate Wildland Fire Behavior (Blended).

References:

S-290, Intermediate Wildland Fire Behavior (Blended)

S-190, Introduction to Wildland Fire Behavior

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Date: Aug 14, 2025
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The S-271, Helicopter Crewmember (Blended) is now available. Developed through the Incident Performance and Training Modernization (IPTM) effort, this training supports individuals working towards Helicopter Crewmember (HECM) incident qualifications. 

S-271, Helicopter Crewmember (Blended) training combines online training and instructor-led training components. This course is designed to provide students with the knowledge and skills necessary to perform the duties of the HECM position, as described in the NWCG Incident Position Standards for Helicopter Crewmember, PMS 350-22.

Any changes to qualification pathways will take effect with the next update of the NWCG Standards for Wildland Fire Position Qualifications, PMS 310-1, scheduled for January 2026.

References:

S-271, Helicopter Crewmember (Blended)

NWCG Helicopter Crewmember (HECM) Position Page

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Incident Position Standards and Next Generation Position Task Books Now Available for FBAN and LTAN

Date: Aug 13, 2025
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NWCG is excited to announce that Incident Position Standards and Next Generation Position Task Books are now available for Fire Behavior Analyst (FBAN) and Long Term Fire Analyst (LTAN).

The Performance Support Packages for these positions were developed as part of the Incident Performance and Training Modernization (IPTM) effort. These resources support trainees, qualified personnel, and evaluators in their respective roles.

Any changes to qualification pathways will take effect with the next update of the NWCG Standards for Wildland Fire Position Qualifications, PMS 310-1, scheduled for January 2026.

References:

NWCG Fire Behavior Analyst Position Page

NWCG Long Term Fire Analyst Page