Grassland Management in Boulder County

After exploring this story map,  please complete this brief, three question survey  Your responses will help determine if this story map is effective at communicating information and resources about grassland management in Boulder County and what should be included in future updates.

While grassland ecosystems are managed to create a high functioning and resilient ecosystem, wildfire risk reduction is not a direct goal because of tradeoffs with maintaining ecosystem function and resilience. Some management practices have the co-benefit of reducing wildfire behavior, which may reduce risk to communities, but no outcome is ever guaranteed. In the year prior to the Marshall Fire, Boulder County land managers grazed their land in the southern portion of the fire perimeter three times. Removal of invasive species, which can lead to higher fire behavior, also occurred on open space throughout the fire perimeter. Finally, selective mowing occurred in some areas adjacent to communities. Areas that were managed did see less intense fire, yet it still spread quickly to unmanaged land and communities in part due to weather conditions and wood fences, which acted as conduits into communities.

A common conversation among land managers is: Do we manage towards predicted average conditions or extreme conditions? Conditions that led to the Marshall Fire’s destruction were, without a doubt, extreme (though not rare or unprecedented) conditions because:

• high amounts of fuel were present from a wet spring,
• no significant snowfall events occurred in the months prior, which led to tall standing dead grasses that led to flame lengths four times as high as if the grasses had been pushed down by previous snow,
• grass fuels were abnormally dry for most of December with low relative humidity, and
• sustained 80+ mph winds with gusts above 100 mph created rapid spreading conditions.

Read more about the  causes of the Marshall Fire  and the conditions that led to it and the emergency response that followed in the  Marshall Fire Facilitated Learning Analysis . In these extreme conditions, the reality is that almost no combination or scale of mitigation practices is able to fully prevent wildfires from spreading as rapidly as the Marshall Fire did, which is why it is important that individuals take specific measures on their property that will help stack the odds towards reducing hazards, and therefore risks.

Despite the devastation that the Marshall Fire caused, large amounts of fuel reduction activities (e.g., grazing and mowing) took place prior to and have continued since in the fire footprint and in many other areas of eastern Boulder County.

The map below displays areas across eastern Boulder County where grassland management and fuel reduction activities, including grazing by cattle or goats and/or mowing are conducted by local municipalities. It does not include work done on private lands. The map depicts planned management for a specific year with data available at the time of map development. Currently, this map only shows data from 2023, and does not include data from 2024 or beyond. It does not indicate areas where management actions have been updated. It is important to note that management actions may have occurred in locations not represented on this map and management actions may have not occurred even if represented on this map. Please contact your local parks and open space representatives for the most accurate and up to date information.

Grasslands in Boulder County are managed for multiple objectives, including enhancing grassland health and resilience, supporting recreational activities, promoting agriculture, and reducing wildfire risks. Wildfire risk reduction might not be the primary focus in some areas depicted on this map.

You can turn different layers on and off, search for addresses, and filter management areas by entity, year (currently, only 2023 data are shown), management type, and grazer type when applicable.

This map was developed by The Watershed Center and the Boulder County Community Planning and Permitting Department in collaboration with multiple entities within the Boulder County Fireshed Grasslands Working Group, including Boulder County Parks and Open Space, City of Boulder Open Space and Mountain Parks, City of Longmont, Town of Superior, City of Louisville, and Town of Erie. Development of this map was funded by the Boulder County Wildfire Mitigation Tax.

Below are links to websites and additional story maps developed by local municipalities regarding wildfire mitigation. Please use these links and/or contact your local open space representatives directly for questions regarding grassland management in your county, city, or town.

Boulder County -  Forest and Grasslands Management website 

City of Boulder -  Wildfire Resilience in City of Boulder Open Space website 

City of Longmont -  Wildland Firefighting Home Tips website 

City of Lafayette -  Wildfire Awareness website 

City of Louisville -  Wildfire Risk Assessment story map ,  Wildfire Mitigation story map 

Town of Superior -  Enhancing Community Resiliency website ,  Wildfire Mitigation story map 

Town of Erie -  Open Space Management ,  Wildfire Mitigation website 

While local municipalities and some private landowners are managing grasslands and trying to reap as many co-benefits for fire risk reduction as possible, protection of individual homes and communities is still a partnership between municipalities, individuals, and communities. The most important measure that you can take as a homeowner is to have a defensible home ignition zone, which includes your home itself and the 5-10 feet area around it. This means:

• constructing your home with nonflammable materials,
• clearing flammable vegetation and debris away from your home and nearby structures like sheds,
• and limiting the use of wooden fencing (which was a major contributor to the rapid spread of the Marshall Fire through communities).

If you choose to plant vegetation five to 30 feet from your home, follow these  guidelines.  Plant native, deciduous trees, low-growing shrubs, grasses, and wildflowers, and keep them well-spaced, well-pruned, and watered, especially during the winter. Having hardened homes is crucial at the grassland-urban interface and the several rows of homes into subdivisions. Effectiveness multiplies when this is done at a community level.

For more detailed information on home hardening and the home ignition zone, see Colorado State Forest Service's  Home Ignition Zone guide  and  Home Ignition Zone checklist .

 Wildfire Partners  - Boulder County’s wildfire mitigation program—educates, motivates, and supports Boulder County residents in preparing for future wildfires. The program is based in the county’s Community Planning and Permitting Department and is funded by the Boulder County Wildfire Mitigation Tax. Wildfire Partners offers several county-wide programs including:

• Strategic fuels mitigation grants
• Community mitigation planning
• Community chipping
• Rebates
• Outreach and education
• Youth program: Youth Helping Underserved People and Communities

Additional programs are being developed for 2025. Learn more about  Wildfire Partners  and  Boulder County wildfire mitigation programs . You can also access information about defensible space, home hardening, landscaping with low-flammability vegetation, and much more!

If you choose to do any of the actions listed below, please check your local laws and regulations to make sure that you are in compliance.

• If you believe overgrown vegetation on open space land adjacent to your property is a possible hazard, contact the  Weed Control Department . Staff will look at various risk models to determine if the location is at a higher risk for fire and mow if necessary, where possible.
• If an irrigation ditch runs through your property and you are interested in removing vegetation for fire mitigation, contact the ditch company before doing any work yourself.

• Request a free City of Boulder  Wildfire Home Assessment  to assess your property for wildfire risk.
• If an irrigation ditch runs through your property and you are interested in removing vegetation for fire mitigation, contact the ditch company before doing any work yourself.

• The City of Longmont mows a strip of grassland along private properties that border City of Longmont Open Space depending on weather conditions and vegetation growth. Homeowners should reach out to the City of Longmont Call Center at 303-651-8416 if that is not happening.
• If an irrigation ditch runs through your property and you are interested in removing vegetation for fire mitigation, contact the ditch company before doing any work yourself.

• If an irrigation ditch runs through your property and you are interested in removing vegetation for fire mitigation, contact the ditch company before doing any work yourself.

• You are allowed to mow a buffer extending up to 10 feet on to City of Louisville Open Space from your property line. If unsure of your neighboring parcels' land ownership, check ownership using the Boulder County Assessor's Office Property Search, as joint-owned and Boulder County lands have differing regulations. If you mow a buffer, ensure mowing/weed whacking equipment is free of any mechanical defects that could cause a spark. Be aware of any rocks or debris on the ground and leave six inches of clearance to avoid causing a spark. If vegetation is not green, equipment should be fitted with a spark arrestor (On the Land 2023). Finally, be sure to have a person watching the equipment at all times while the engine is running, and keep a fire extinguisher or water source in close proximity. Note that it is not allowed to mow on Red Flag Warning days, and some fire bans may prohibit any access over vegetation by motorized equipment, such as ride mowers.
• Contractors working on multiple properties and/or a “neighborhood property line” must  apply for and receive an access permit  before proceeding so the City will know when they will be on-site, can brief the contractor on all safety and land use information, and can coordinate the activity with the City’s other maintenance operations.
• If an irrigation ditch runs through your property and you are interested in removing vegetation for fire mitigation, contact the ditch company before doing any work yourself.

• If you believe overgrown vegetation on open space land adjacent to your property is a possible hazard, report your concerns to  Superior Click and Fix  24 hours a day, 7 days a week.
• If an irrigation ditch runs through your property and you are interested in removing vegetation for fire mitigation, contact the ditch company before doing any work yourself.

• If an irrigation ditch runs through your property and you are interested in removing vegetation for fire mitigation, contact the ditch company before doing any work yourself.

Fire specialists within Boulder County are seeking residents who want to be “spark plugs” and advocates for wildfire awareness for their communities. Become aware, knowledgeable, and interactive with the Boulder County and local  Community Wildfire Protection Plans (CWPPs)  for your area.

Boulder County updated their CWPP in the fall of 2024. The CWPP was updated using a collaborative process including local, state, non-government, and federal representatives with expertise. Wildland fire experts from the Colorado Forest Restoration Institute, Rocky Mountain Research Station, Missoula Fire Lab, and Cal Fire as well as local fire protection districts, open space and resource managers, and municipal managers were also consulted.

See the fully adopted and signed  Boulder County CWPP  and access the  interactive Boulder County CWPP story map . The story map will be updated periodically as management recommendations and projects are completed and as changes occur to keep the CWPP relevant and up to date.

A list of grassland management practices that have previously been used in Boulder County or thought to be effective at reducing fire risk is below. It is crucial to understand that no single management strategy will be 100% effective at reducing fire risk, and that even the most effective implemented management cannot guarantee a specific outcome. Instead, a combination of management practices should be used depending on local conditions, season or time of year, type of land (e.g., open space adjacent to communities, agricultural land, recreation land, proximity to other wildlife populations, etc.), and type of specific vegetation (Leis 2013). The application of these strategies will depend on management goals of specific local government municipalities (i.e., desired future conditions).

While not considered grassland management practices, other grassland features affect wildfire behavior and risk. Prairie dog colonies and wetlands and riparian areas in native prairie are natural features and have historically been part of this ecosystem. Irrigation ditches and irrigated agriculture are human-made and embedded within the grasslands. Features discussed below include:

• Prairie dog colonies
• Wetlands and riparian areas
• Irrigation ditches
• Irrigated agriculture

To learn more about fire-related knowledge gaps in the grasslands and to begin to address them, research occurs on open space lands throughout Boulder County.

The City of Boulder Open Space and Mountain Parks, Jefferson County Open Space, Boulder County Parks and Open Space, and City of Longmont each operate small grant programs. In 2023, these agencies collaborated to provide funding for Jonathan Henn, a post doctoral researcher at the University of Colorado Boulder, to conduct a study titled “Understanding spatial variation in grassland fuels to inform wildfire risk mitigation strategies in the Front Range.” Additional funding and support was provided by the Joint Fire Science Program, City of Louisville, and Town of Superior. This research addresses critical knowledge gaps and contributes to the development of strategies for grassland fuel mitigation. Background information and initial results from 2024 are below:

In 2024, to address how grassland fuels accumulate differently across the landscape in Boulder County, the research team monitored 120 plots that varied in the main plant species present, topography, soil characteristics, etc. Plants were identified to species, and plant height and moisture data were collected. Additionally, living and dead plant matter were clipped and collected. These metrics are important factors that affect fire spread.

While there are not clear differences in fuel between different types of plant communities, there is a lot of variation in how much fuel accumulates across areas. This variability is related to the total plant cover, prairie dog presence, and the types of plants present. Overall, this information will help to better understand where there is more fuel to help prioritize where any fuel treatment activities could take place.

Fuel measurements monitoring will occur at the same monitoring plots through time to examine how metrics change from year to year and across seasons. Another experiment is also being developed to test how effective different fuel management methods are and to examine whether different approaches to fuel management might have other effects on grassland ecosystems like plant diversity and soil health.

Additionally, staff scientists at each agency have conducted their own research on fire related to topics. For example, in 2023, City of Boulder Open Space and Mountain Parks staff conducted a study on the impacts of the Marshall Fire on grasslands and riparian areas. In 2024, they also began a pilot project assessing the feasibility of perimeter mowing in priority areas adjacent to the City of Boulder. Information on that project is below:

In 2024, City of Boulder Open Space and Mountain Parks implemented a perimeter mowing pilot program to reduce risk in grasslands west of Boulder. Pilot areas were located to the south and west of city limits in the Devil's Thumb and Wonderland Lake neighborhoods/open space properties. The project scope included two mowing treatments for each pilot area.

Though the original project scope included two mowing treatments, only one was needed in pilot areas to keep grass heights at the 4-6" target height, likely due to low precipitation during the summer. A key part of this project is monitoring on-the-ground conditions to implement management actions only when necessary.

City of Boulder Open Space and Mountain Parks intends to continue the pilot project into 2025 and intends to include more pilot areas. Targeted grazing and prescribed fire will be added as management techniques alongside mowing when conditions allow.

In the past, City of Boulder Open Space and Mountain Parks, Jefferson County Open Space, Boulder County Parks and Open Space, and City of Longmont small research programs have also supported research projects on the effects of forest fires. Examples include:

• “ Fuels treatments and their impact on carbon stocks and fire severity in Boulder and Jefferson Counties and the City of Boulder ”
• " Forest vulnerability to disturbances and climate change .”

If you would like more information on these studies, please contact  Brian Anacker , Sr. Manager of Science and Climate Resilience at City of Boulder Open Space and Mountain Parks.

If you are interested in learning more about the small grant programs, you can find further information at the following links:

•  OSMP Funded Research Program | City of Boulder (bouldercolorado.gov) 
•  Research on Open Space - Boulder County 
•  Small Research Grants Program | Jefferson County, CO (jeffco.us) 
•  Ecosystem Management Funded Research Program | City of Longmont, Colorado (longmontcolorado.gov) 

 Alison Post – University of Colorado Boulder 

 Jon Henn – University of Colorado Boulder 

 Tim Seastedt – University of Colorado Boulder 

Allison James –  Town of Superior 

Matt Magley –  Town of Superior 

Taylor Smith –  Town of Superior 

Leslie Clark –  Town of Superior 

Brendan Close –  City of Louisville 

Ember Brignull –  City of Louisville 

Jeff Durbin –  City of Louisville 

John Willson –  Louisville Fire 

Brian Anacker –  City of Boulder Open Space and Mountain Parks 

Chris Wanner –  City of Boulder Open Space and Mountain Parks 

Lynn Riedel –  City of Boulder Open Space and Mountain Parks 

Ann Lezberg –  City of Boulder Open Space and Mountain Parks 

Kerry Webster –  City of Boulder Open Space and Mountain Parks 

 Brianna Baker – The Ember Alliance 

 Meg Matonis – The Ember Alliance 

 Chad Julian – Colorado State Forest Service 

 Janae Malpas – Colorado State Forest Service 

Dan Garrett –  Lafayette Fire 

Lexie Sierra Martinez –  City of Lafayette 

Rob Burdine –  City of Lafayette 

Dan Higgins –  Longmont Fire 

David Bell –  City of Longmont 

Jim Krick –  City of Longmont 

David Hirt –  Boulder County Parks and Open Space 

Joe Swanson –  Boulder County Parks and Open Space 

Stefan Reinold –  Boulder County Parks and Open Space 

Meg Halford –  Boulder County Community Planning and Permitting 

Ed LeBlanc –  United States Forest Service 

Joel Brunger –  Town of Erie 

Mike McGill –  Town of Erie 

 Matt Bitters – The Watershed Center 

 Yana Sorokin – The Watershed Center 

 Kirin Riddell – Boulder Watershed Collective 

 Maya MacHamer – Boulder Watershed Collective 

 Steve Orr – Fire Adapted Colorado 

 Jack Pritchard – National Forest Foundation 

 Jenny McCarty – St. Vrain and Left Hand Water Conservancy District 

 Boulder County Fireshed 

 Boulder County Wildfires Story Map 

 City of Boulder Open Space Wildfire Risk Management 

 City of Longmont Wildfire Awareness 

 City of Lafayette Wildfire Awareness 

 City of Louisville Open Space 

 Town of Superior Open Space 

 Town of Erie Wildfire Awareness 

 US Forest Service National Cohesive Wildland Fire Strategy 

 Sheriff's Investigation Report 

 Facilitated Learning Analysis 

 Wildfire Partners 

 CSFS Home Hardening 

 CSFS Plant Flammability List 

 Superior Click and Fix (to report overgrown vegetation concerns) 

 City of Boulder Wildfire Home Assessment 

 Unincorporated Boulder County Weed Control Contact (to report overgrown vegetation concerns) 

 City of Boulder OSMP 

 City of Longmont POS 

 Boulder County POS 

 Jefferson County POS 

 Funded Research Contact 

 Community Wildfire Protection Plans 

 Boulder County Irrigation Ditches 

 Boulder County Property Search 

 City of Boulder OSMP Grassland Plan 

 City of Boulder OSMP Master Plan 

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Kaufmann, M.R., Veblen, T.T., and Romme, W.H. 2006. Historical fire regimes in ponderosa pine forests of the Colorado Front Range, and recommendations for ecological restoration and fuels management. Northern Arizona University.  https://openknowledge.nau.edu/id/eprint/2566/1/Kaufmann_M_etal_2006_HistoricalFireRegimesColoradoFront.pdf 

Leis, S.A. 2013. Fuels management in the Great Plains. Great Plains Fire Science Exchange, GPE publication #2013‐28. https://gpfirescience.org/wp-content/uploads/2022/05/GPEFuelsManLeis201328-3.pdf

Norman, L.M., Lal, R., Wohl, E., Fairfax, E., Gellis, A.C. and Pollock, M.M., 2022. Natural infrastructure in dryland streams (NIDS) can establish regenerative wetland sinks that reverse desertification and strengthen climate resilience. Science of the Total Environment 849:157738.  https://doi.org/10.1016/j.scitotenv.2022.157738 

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Prevéy, J.S. and Seastedt, T.R. 2015.  Effects of precipitation change and neighboring plants on population dynamics of Bromus techtorum. Oecologia 179:765-775. https://doi.org/10.1007/s00442-015-3398-z

Ratcliff, F., Rao, D., Barry, S., Dewees, S., Macaulay, L., Larsen, R., Shapero, M., Peterson, R, Moritz, M., and Forero, L. 2022. Cattle grazing reduces fuel and leads to more manageable fire behavior. California Agriculture 76(2-3):60-69. https://doi.org/10.3733/ca.2022a0011

Rouet-Leduc, J., Pe'er, G., Moreira, F., Bonn, A., Helmer, W., Shahsavan Zadeh, S. A. A., Zizka, A., and van der Plas, F. 2021. Effects of large herbivores on fire regimes and wildfire mitigation. Journal of Applied Ecology 58:2690– 2702.  https://doi.org/10.1111/1365-2664.13972 

Veblen, T.T. and Donnegan, J.A. 2005. Historical range of variability for forest vegetation of the National Forests of the Colorado Front Range. USDA Forest Service. https://www.fs.usda.gov/Internet/FSE_DOCUMENTS/stelprdb5386430.pdf

Veblen, T.T., Kitzberger, T., and Donnegan, J.A. 1996. Fire ecology in the wildland/urban interface of Boulder County. City of Boulder Open Space. https://webappsprod.bouldercolorado.gov/openspace/research-reports/docs/3163_Veblen_Thomas_Fire-1-201307161221.pdf

Zouhar, K. 2021. Fire regimes of plains grassland and prairie ecosystems. In: Fire Effects Information System. USDA Forest Service, Rocky Mountain Research Station, Missoula Fire Sciences Laboratory. www.fs.usda.gov/database/feis/fire_regimes/PlainsGrass_Prairie/all.html