Overview
Gallatin County launched a wildfire mitigation program in late 2022 to help residents reduce wildfire risk on their properties. The program provides guidance to property owners on steps they can take to improve wildfire safety and is also seeking cost-share funding to help cover the costs of mitigation projects.
Wildfire Risk in Gallatin County
Gallatin County has a moderate to high wildfire risk, ranking in the 74th percentile nationally. Risk varies across the county, with some areas, such as Big Sky, ranking much higher. Differences in geography, vegetation, and weather create varying wildfire risks throughout the county.
More information about local wildfire risk can be found in Gallatin County’s 2026 Hazard Mitigation and Community Wildfire Protection Plan, which includes a detailed Wildfire Hazard Profile.
Fire Adapted Gallatin Working Group
Many local, state, and federal organizations help support wildfire mitigation efforts in Gallatin County. The Fire Adapted Gallatin Working Group helps coordinate these programs. The County’s Preparedness and Mitigation Manager serves as a main point of contact, helping property owners find the programs and resources that best fit their needs.
Wildland Urban Interface
Gallatin County’s 2026 Wildland Urban Interface (WUI) map was developed through a collaborative Quantitative Wildfire Risk Assessment (QWRA) conducted by Vibrant Planet/Pyrologix for Gallatin, Park, Stillwater, and Carbon Counties. The assessment followed the methodology outlined in General Technical Report 315 (Scott et al., 2013) and produced what Vibrant Planet calls a Functional Wildland Urban Interface, which incorporates additional wildfire risk factors beyond traditional WUI mapping.
Planning partners determined that the Functional WUI’s Direct Exposure and Structure Transmission Zone layers provided a strong foundation for defining the WUI when combined with municipal watersheds and major evacuation routes. This approach uses more detailed data and focuses on areas where wildfire would pose a direct threat to structures, resulting in a more accurate representation of risk.
One notable improvement is the depiction of the Gallatin Valley floor. The 2020 WUI map classified much of the valley floor as a single, continuous interface area based largely on fixed distance criteria. In reality, wildfire risk occurs in smaller, more isolated pockets. The previous methodology also often placed WUI boundaries midway up slopes, whereas wildfire behavior suggests that fires occurring anywhere on a slope can threaten structures similarly, and fuel treatments are often most effective near ridge tops.
The 2026 mapping addresses these limitations by using the Structure Transmission Zone, which identifies areas within 2.4 kilometers of structures where wildfire could directly threaten those structures. This approach captures vulnerable slopes more effectively and better reflects actual wildfire risk.
For the service area, the Wildland Urban Interface is defined as the combination of Direct Exposure areas, Structure Transmission Zones, municipal watersheds, and buffered major transportation corridors that serve as evacuation routes where those corridors were not already included in the WUI.
The spatial criteria for mapping WUI in this Gallatin County CWPP are:
- Direct Exposure – Zone of burnable land cover near (within 75 m of) a structure. Reducing fire intensity and ember production in this zone would reduce the exposure of nearby buildings to heat and embers. Buildings in this zone also require hardening of the structure to resist ignition.
- Structure Transmission Zone – Unpopulated land within about 2.4 km of a group of structures. Fires that originate within or spread to the STZ have an immediate threat of reaching the nearby structures; fuel treatments that slow fire spread in this zone can reduce risk to these structures.
- Municipal Water Sheds – Confines of the watersheds for Hyalite Creek and Bozeman Creeks that make up the Bozeman Municipal Watershed. The Lyman Creek Watershed is already contained in the Structure Transmission Zone.
- Evacuation Routes – Major travel corridors that serve high use areas with limited access has a 200 meter buffer off centerline added.
Wildfire Risk Data
The 2026 Quantitative Wildfire Risk Assessment produced many detailed datasets describing wildfire risk across the service area. Because the data are very detailed, they can be difficult to display on static maps. The online web map allows users to turn layers on and off to explore specific risk information.
Ember Load
The Conditional Ember Load Index is an index of the relative number of embers that land at a given landscape location, including embers that land on non-burnable pixels that do not produce embers. The cELI does not account for burn probability and can be used to identify where on the landscape hardening buildings to resist ember ignition may be needed.
Ember Production
The Conditional Ember Production Index is an index of the relative number of embers lofted at a given landscape pixel if a fire were to occur. The cEPI represents the relative number of embers produced at a pixel as a function of the fire environment. Being “conditional,” cEPI does not account for variation in burn probability across the landscape.
Embers to Buildings
Conditional sources of ember load to buildings is a relative index of the number of embers lofted that eventually land on a pixel with building cover. cSELB is a unitless index. WildEST uses the Wildfire Risk to Communities Building Cover dataset as ember targets. WildEST tracks all embers that land on pixels with nonzero BuildingCover and assigns to the lofting pixel their load as a source of embers to buildings. The result is a raster representing the sources of production of embers that land on or near buildings, which can be useful for fuels management and response planning.
Wildfire Exposure Score
Wildfire Exposure Score (WES) is an integrated measure combining the likelihood of wildfire (Burn Probability) with potential consequences of wildfire to resources or asset at a given location (Damage Potential). In this dataset, consequence is modeled using a response function that accounts for potential loss to structures as a function of flame length, along with ember exposure from nearby vegetation. Together, these factors provide a general estimate of potential wildfire damage to homes (regardless of the actual presence of a building).
Fire Intensity Threat to Egress Routes (FITTER)
To meet National Fire Danger Rating System radiant heat standards, a safety zone must be situated at a distance of at least four times the flame height. (NWCG Incident Response Pocket Guide (IRPG), PMS 461, 2025). The FITTER index identifies areas on and alongside egress roads that would be considered unsafe under 95th percentile flame length (qFL) conditions. Since flame length is greater than or equal to flame height, the FITTER index produces a more conservative estimate by incorporating qFL.
Home Preparedness Steps
Step 1 – Self Assessment
Conduct a self assessment of your property.
Conduct a Self-Assessment of Your Property
Many guides are available to help homeowners reduce wildfire risk, and most offer similar recommendations for both homes and surrounding property. Simple actions—such as cleaning gutters, screening vents, moving firewood piles away from structures, and clearing combustible materials—can significantly improve a property’s resilience to wildfire with relatively little effort.
Gallatin County recommends that property owners begin by conducting a self-assessment of their property. This is an easy first step that can help you identify opportunities to reduce wildfire risk and establish a baseline understanding of your property’s conditions. Completing a self-assessment also gives you time to identify specific questions or concerns to discuss during a professional home wildfire risk assessment.
While there are many resources available, most wildfire mitigation recommendations focus on two primary goals:
- Reducing wildfire intensity around your home and property.
- Reducing opportunities for ignition of structures and other assets.
Taking proactive steps in these areas can greatly improve your property’s ability to withstand a wildfire.
Reducing Wildfire Intensity
Whether a wildfire starts on your property or spreads onto it, its behavior is driven by three main factors: vegetation (fuel), weather, and terrain. While we cannot control the weather or terrain, we can manage the vegetation around our homes and property.
Well-maintained vegetation reduces the amount of fuel available to burn, which lowers fire intensity and the potential for extreme wildfire behavior. Removing dead vegetation, mowing grass, increasing spacing between trees and shrubs, pruning lower tree branches, and planting fire-resistant vegetation near your home can help reduce wildfire risk. These actions can make a fire less intense and easier for firefighters to control.
Reducing Opportunities for Ignitions
The second part of wildfire preparedness is reducing the chances that your home will catch fire. Most homes lost during wildfires do not ignite because flames directly reach the house. Instead, wildfires often send burning embers ahead of the main fire. These embers can land on dry, flammable materials and start small fires around a home.
To reduce this risk, we try to eliminate places where embers can easily start a fire. This includes using fire-resistant landscaping, increasing the spacing between trees and buildings, and maintaining the home itself. Important actions include using noncombustible building materials, cleaning debris from gutters and eaves, covering vents and crawlspaces with screens, removing vegetation and debris from under decks, and storing firewood and other combustible items away from the house.
In short, the goal is to remove as many ignition risks as possible so that if burning embers land near your home, they are less likely to start a fire.
Preventing Home Ignition
Step 2 – Professional Home Risk Assessment
Request a Home Risk Assessment by a professional from Gallatin County.
Gallatin County offers free, in-person home assessments to help property owners identify wildfire risks. During the visit, a wildfire professional will evaluate your property, answer questions, provide personalized recommendations, and discuss practical steps you can take to reduce wildfire risk around your home.
Contact us to set up an assessment.
Step 3 – Discuss Approaches to Conducting Work
Many of the items identified during your home risk assessment, or in follow up evaluations, can be completed by homeowners. In some cases specialized skill or equipment may be needed. Regardless of how you decide to implement work, Gallatin County Emergency Management can provide you with a “treatment plan” that outlines the work we recommend for your property.
Based on available program funding, we may also be capable of entering into a cost share program for work done on your property, excluding work on the physical buildings.
Available options for completing work, and available funding, will be discussed with you when your home risk assessment is completed.
Homeowner Work
In many situations a lot of the recommended work can be completed by homeowners either with hand tools or rented equipment. It is also possible that project work could be split between work you do, and more complex work you hire a contractor for.
Typically, there are a lot of simple tasks that can easily be done by the homeowner to make their property more resistant to fire, it will just take their time.
Contracted Work
It’s very possible that if trees need to be thinned out, a lot of understory is present, or you have a large parcel, that you won’t have the skills, equipment or time to do the work. In this situation, hiring a contractor makes sense. Several contractors are present in the area and could implement the prescription for your property. When a contractor is utilized, and cost share programs are available, the property owner typically pays their portion with cash and the rest is reimbursed by the County (typically a 60% grant, 40% land owner cost share).
Interested?
Sound like something you’d like to learn more about?
Reach out and let’s talk.