Illustration by Jessy Stevenson

A Glossary of Wildfire Terms You Need to Know

If you live in a wildfire-affected area, it's important to know the lingo

Wildland firefighting is full of jargon that can be tough to decipher (a Forest Service glossary of wildfire terms runs nearly two hundred pages), but critical for nearby residents to know for getting a grasp of what’s happening on the ground. Understanding how fires behave, what containing them actually means, and the complexities of a wildland fire operation can help people affected by burns breathe a little easier in the smoky air.

Firefighting teams look at fuel, weather, and topography, or the layout of the land they approach. They can manipulate the fuel; the rest informs the safety and strategy of the operation. So the key to wildland firefighting is eliminating fuel, or the stuff that burns.

Fireline — A line of ground without vegetation that will presumably stop or direct a fire’s progress. Firefighters dig line by hand, using Pulaskis, McCleods, and other tools. Bulldozers and other heavy equipment are also used to make larger firelines.

Backburn, backfire, and burnout — terms for intentionally putting fire on the ground and burning vegetation against an active flame front to deprive it of fuel.

Indirect attack — a method of fighting a fast-moving or high-intensity wildfire that uses existing fuel breaks to stop a fire’s advance. A control line is staged at an existing feature, like a road, or firebreak, lake, or river, often far from the fire’s front.

Direct attack — any action that directly engages a fire. This can be digging fireline, spraying water, or dropping retardant from the air.

Black — the area that’s already burnt. A common saying in wildland firefighting is “keep one foot in the black.” That means, always have an already burned area you can escape into, since that likely won’t burn again.

Green — fuel-laden area that hasn’t yet burned.

Anchor point — a strategic location from which to start building fireline. The goal of an anchor point is to prevent the fire from burning around the fireline, pinning firefighters from behind.

Control line — any constructed or natural barrier used to impede a fire’s progress.

LCES (lookout, communication, escape routes, safety zones) — safety essentials of any wildfire operation. Lookouts are scouts, positioned to watch both impending fires and fire crews, to warn of any potential disasters.

Illustrations by Jessy Stevenson

Communication — refers to how information is conveyed to crews on the ground—this could be from radio to word of mouth.

Escape routes — are how firefighters will get to safety, should the situation become unsafe on the ground.

Safety zones — are areas where firefighters can find respite from a dangerous situation. All elements of LCES may shift in just a matter of hours as fires change behavior. Values at risk the things threatened by a wildfire. Often, this refers to homes and private property. But values at risk can also include water supply, power grids, and cultural or historic areas that a wildfire might destroy or alter.

Size up — the process of quickly and accurately assessing a fire and its critical characteristics. This should include a name for the fire, its location and size, an assessment of the terrain, values at risk, weather conditions, the fire’s behavior, what resources are needed, and what caused the fire (if known).

Mop up — cleaning up an area that has burned. This can include tending to dangerous trees, removing remaining fuel that could reignite, trenching logs so they don’t roll, and anything else to make the scene as safe as possible.

Incident Action Plan (IAP) — a plan of action covering twelve to twenty-four hours, developed by the incident commander assigned to a wildfire. IAPs specify the tactics and support activities planned for a certain time period.

Incident commander — the head honcho on a fire and one of as many as dozens of people managing the complex planning, safety, strategy, and operations on a conflagration.

Hand crew — general-purpose wildland firefighters. Hand crews are typically eighteen to twenty people and work on digging line, clearing trees and brush with chainsaws, and setting controlled burns with drip torches. The Forest Service specifies three crew Types, referring to the experience and capabilities of the group. A Type 1 crew is a team of Hotshots. A Type 2 IA crew is less experienced than a team of Hotshots, but can break up into 4-6 person teams to engage in initial attack (IA) with the fire. Type 2 crews are more entry level. They do not engage in initial attack, but dig line and engage in other critical work less close to the fire.

Engine crew — a team of up to ten firefighters attached to a fire engine, tasked with initial, direct engagement of a wildfire. They use a variety of tools, primarily relying on hoses and water.

Hotshots — an intensively trained team of firefighters primarily tasked with directly engaging a fire and digging hand lines.

Helitack crew — a team of firefighters trained and certified in the use of helicopters to fight fires. Helitack crews are transported into fires to directly engage the flames and are often the first people responding to the incident.

Dozer — a heavy machine with steel tracks and a front-end blade. Designed for clearing trees, brush, logs, and other materials down to the mineral soil.

Air tanker — a fixed-wing aircraft designed or retrofitted to transport and deploy fire retardant directly to fire or adjacent land. The Forest Service uses a variety of aircraft with capacities ranging from eight hundred to eight thousand gallons.

Tender — any kind of ground vehicle tasked with supporting a critical wildland firefighting asset. Tenders can deliver fuel and repairs to dozers, refill helicopters or planes with fuel, or deliver water to engines.

Engine — a truck or other ground vehicle that can transport and pump water, via hoses, onto a fire. Fine fuels fast-drying, highly flammable materials such as grass, leaves, or pine needles, less than a quarter inch in diameter.

Helibucket — a bucket that hangs from a helicopter by a cable and is used to transport and apply water or retardant directly onto a fire. Helibuckets can be dropped into a lake or river to refill with water and can hold as much as twenty-six hundred gallons. That water can be dropped directly onto a fire.

Parallel attack — a fire suppression tactic in which a line is dug approximately parallel to the fire’s front, but some distance away. Once the parallel line is set, firefighters set fire to the ground between the line and the fire, robbing the fire of fuel and stopping its advance.

Swamper and faller — a faller cuts down trees using an ax or chainsaw. This role requires skill and experience with tools and knowledge of tree characteristics and behavior. A swamper supports the faller by clearing brush, trimming limbs, shuttling supplies such as fuel, and watching for danger.

Dirty August — a firefighter term for a month when fires in the West tend to increase in size, severity, and complexity.

Nomex — a brand of flame- and heat-resistant material worn by firefighters.

Head — imagine a fire like a charging bull. The head of the fire is the horns, where the fire is stomping ahead at full force.

Flank — the sides of the fire, to the left and the right of the head.

Rear — the part of the fire opposite of the head. To continue the analogy above, the rear of the fire is the bull’s kicking hind hooves.

Purchase your copy here

Rate of spread — the speed at which a fire is moving from its origin point, usually affected by wind, moisture, and slope.

Chain — a unit of measurement, commonly used in wildland fires. Eighty chains equal one mile, so one chain is sixty-six feet long.

Fire fingers — long, narrow sections of fire extending out from the fire’s primary front.

Pockets — unburned areas between the fire’s fingers and the main front of flames.

Island — an area of unburned land within the perimeter of a fire. Wildfires don’t always torch everything in their path.

Spot fire — an occurrence when embers drift from the main fire and settle on vegetation or other flammable material, igniting new flames.

Flashy — fuel light, highly flammable materials such as grasses, shrubs, leaves, or needles. These fuels are often the cause of home ignitions.

Torching — when one or more trees go up in flames.

Ladder fuels — flammable materials, like low limbs and small, young trees, that can allow a fire to move from the forest floor up into the canopy, increasing the intensity and potential growth of a fire.

Widow-maker — a safety hazard for firefighters in which a branch or treetop is loose from the main tree. When that tree is cut down, the loose limb may fall off away from the main tree, potentially onto the firefighter below.

Snag — a dead, often fire-killed, standing tree that presents a hazard for firefighters on the ground.

Slopover — when a fire spreads outside the perimeter of a control line.

Ground, surface, and crown fires — a ground fire burns mostly below the surface of the earth, on roots and in duff on the forest floor. A surface fire burns pine needles, shrubs, and small trees on the forest floor. Here, flames might be immediately visible. When those fires grow larger and “ladder” up trees, they can ignite crown fires. That’s when the canopies of trees light with flame. These are often the largest, hardest to contain, and fastest-moving fires. When one canopy ignites, that fire can begin jumping from tree to tree.

Fire triangle — heat, oxygen, and fuel. Fires need all three components to burn. Firefighting works by depriving fires of their fuel.

* * *


* * *

From This is Wildfire: How to Protect Yourself, Your Home, and Your Community in the Age of Heat by Justin Angle and Nick Mott, with illustrations by Jessy Stevenson, out now from Bloomsbury Publishing. Copyright © 2023 by Justin Angle and Nick Mott. Illustrations Copyright © 2023 Jessy Stevenson. All rights reserved.

Justin Angle is a professor and the Poe Family Distinguished Faculty Fellow at the University of Montana College of Business and the host of the Fireline podcast, produced by Nick Mott. His work has been published in Journal of Marketing, Journal of Consumer Research, and the Washington Post.

Nick Mott is a journalist and podcast producer. His podcast work has received a Peabody and two National Edward R. Murrow Awards and he is the producer of the Fireline podcast, hosted by Justin Angle. His print and audio reporting has been published in The Atlantic, NPR, High Country News, and The Washington Post, among many other outlets.