Cheatgrass Mitigation Program

Treatment Areas

**Updated 12:42pm August 11, 2023**

Helicopter aerial treatments are complete for 2023.

Starting early August, 2023, aerial cheatgrass treatments will begin. Weather depending, treatments will take place in the in the following locations: National Elk Refuge, Crystal Butte (near Nelson Drive), East Gros Ventre Butte (along Highway 89 from the National Museum of Wildlife Art towards Town of Jackson), State Land on East Gros Ventre Butte, Vogel Hill, High School Butte, Boyles Hill, South-facing slopes along Highway 89 (south of town from Smiths towards Hoback Junction), Hoback Junction toward Stinking Springs.

The Jackson Hole Weed Management Association (JHWMA) and Teton County Weed and Pest District (TCWP) are conducting the second round of treatments for the Cheatgrass Mitigation Program in early August 2023. Treatments will be conducted by helicopter and will take place in wide swaths of the valley.

Cheatgrass is a highly invasive, non-native annual grass with a quick growing life cycle giving it a competitive advantage over native vegetation. This mitigation program is expansive with the goal of reaching over 7,000 acres next month from the Gros Ventre to the Hoback Canyon.

Previous Management

2017 - Pilot Study

In 2017, the JHWMA and TCWP partnered with the University of Wyoming to conduct a pilot study on state land on East Gros Ventre Butte. This study evaluated aerial applications of the newly available herbicide indaziflam and imazapic, the herbicide previously used for cheatgrass management. While this study was small and simple in design, data followed the same trends found in larger studies conducted at Colorado State and other universities. Indaziflam provided the best control of cheatgrass with the least impacts on native vegetation.

Did you know?
Cheatgrass seeds are viable in the soil for 5 years?

2020 - Large Scale Management

Following the success of the 2017 Pilot Study, the JHWMA and TCWP organized partners for a large scale project in 2020. This project treated over 4000 acres of cheatgrass from Stinking Springs in the Hoback to the National Elk Refuge near Kelly.

2020 Partners: Wyoming Game and Fish, Teton Conservation District, Wyoming Wildlife and Natural Resource Trust, Rocky Mountain Elk Foundation, Governor's Big Game License Coalition, Wyoming Wild Sheep Foundation, The National Elk Refuge, and Bridger-Teton National Forest.

Did you know?
Prior to 2020, aerial herbicide applications were not allowed within the Bridger-Teton National Forest. Previous herbicide applications were made by backpack or horseback sprayers.

Current Management

2023 treatments will begin in early August and will again be conducted by helicopter and unmanned aerial aircraft (drones). Landowners have been contacted for permission to treat on private property, and landowners and businesses adjacent to treatment areas have been notified.


Cheatgrass (Bromus tectorum)  germinates in autumn which makes  treatment in August  imperative. This invasive grass out competes natives and perennial grasses from water and nutrients. This significantly diminishes the quality of wildlife habitat, especially the critical mule deer and bighorn sheep  winter range.


Typically this time of year brings with it wildfires, and cheatgrass is a major player. Cheatgrass dries early in the summer making it a serious fire risk, potentially leading to more frequent and larger fires and further habitat loss. As seen last season, a mere lightning strike can ignite an aggressive fire in dry cheatgrass infested lands. Examples of this were the 2019 fires on East Gros Ventre Butte that burned more than 300 acres (Wildlife Museum Fire - 80 acres and Saddle Butte Fire - 250 acres).

Indaziflam (Rejuvra)

Indaziflam is a pre-emergent herbicide that prevents germination of seeds but does not impact growing plants. It remains viable in the soil for 3 years. Because cheatgrass seeds are viable for 5 years, two applications are necessary to prevent additional germination.

Studies indicate that established native perennials, including bunch grasses, are not impacted by indaziflam. Additional studies indicate that native perennial forbs flourish after cheatgrass management begins likely due to a reduction in competitive stress.

Native annual species are impacted by indaziflam. Seedbanks that are viable longer than 6 years may reestablish on their own. In other areas reseeding of native annuals may be necessary.

Additional Information

Will my property be sprayed?
Only properties that received and returned a Cheatgrass Permission request will be sprayed.

I received and returned a Cheatgrass Permission request. Will my entire property be sprayed?
In most cases, no. Cheatgrass is most prominent on steep slopes, and only areas with extensive cheatgrass infestations are targeted for this project.

How close will the helicopter come to my house and/or buildings?
We anticipate a buffer of approximately 300 feet around structures.

Is it safe for animals to graze on treated areas after spraying?
Yes, Rejuvra allows for grazing immediately after treatment.

What if I have cheatgrass within 300 feet of my home and/or buildings?
Steep slopes may be treated by UAV (drone) which has less drift potential and allows for safe treatment closer to buildings. For additional questions about this treatment strategy and timing of this application contact Mark Daluge (TCWP Office phone: 307-733-8419).

Should I be inside/close my windows during the application?
Due to the 300 foot buffer, that is not necessary, but you may do so if you so chose.

How long until I can re-enter the areas that have been treated?
Stay out of treated areas until the spray is dried (time is dependent on weather conditions).

What precautions are in place for sensitive areas?
Areas in and around streams, creeks, ponds, homes, structures, and other sensitive areas will be buffered from treatment by a minimum of 300 feet to ensure that spray drift does not enter those areas. Weather will be monitored and treatments halted if conditions are unfavorable for applications. Pilots are licensed helicopter pilots as well as certified pesticide applicators. Pilots employ both GPS and paper maps to ensure precise treatments.