Second round of aerial cheatgrass spraying planned for Squirrel Creek Wildfire area

Media Contacts: Aaron Voos (USFS),307-745-2323, or
Robin Kepple (WGFD), 307-777-4523,



News Release (PDF)


(LARAMIE, Wyo.)  August 9, 2019 – The Laramie Ranger District and the Wyoming Game & Fish Department (WGFD) are planning to treat cheatgrass within the 2012 Squirrel Creek Wildfire area through the aerial application of herbicide (Imazipic/Plateau).


Aerial spraying with a helicopter is scheduled to begin Aug. 16 on approximately 3,000 acres of the Medicine Bow National Forest, some Wyoming State Land acreage, as well as several private parcels. Treatment units are on the eastern side of the Snowy Range, on the southern end of the Sheep Mountain unit, east and south of Lake Owen, and north of Highway 230.


Treatment should take place over nine days within a 13-day window, and weather-permitting, is anticipated to be completed prior to big-game archery season, which begins Sept. 1.


The helicopter will be based at Forbes/Sheep Mountain Wildlife Habitat Management Area. Public access to the parking lot will be closed during the duration of the project, from Aug. 16 until Aug. 31. Foot traffic onto the property will be allowed.


The emphasis is on controlling non-native, annual cheatgrass on critical big-game winter ranges, enhancing native vegetation species, stabilizing soils, and reducing erosion. Treating cheatgrass also greatly minimizes the risk of a second wildfire in this area by the reduction in fine fuels and diminishes the threat of shorter fire intervals in the future.


In the summer of 2012 the Squirrel Creek Wildfire burned approximately 10,587 acres in the treatment area, which allowed for the inception of cheatgrass as dominant vegetation.


The initial Squirrel Creek Cheatgrass treatment took place in August of 2016, when 2,986 acres of cheatgrass were treated with Imazapic. The outcome of that treatment was very successful, resulting in almost 90% initial reduction of cheatgrass within some of the units. However, studies support current on-the-ground observations, which is that every year post treatment the chemical loses its effectiveness and in order to achieve the desired level of control, 2-3 treatments are necessary.  


Remote sensing images and field data were used by Colorado State University PhD candidate Amanda West, in a coordinated effort with the U.S. Forest Service, to map cheatgrass probability within the fire scar. The finished product is now being used to better focus the aerial application efforts and for treatment efficacy.


“This aerial spraying is a collaborative effort with our partners to address cheatgrass, an increasingly problematic invasive species,” said Jackie Roaque, Rangeland Management Specialist for the Laramie Ranger District. “The effectiveness of the spraying in 2016 shows that aerial application is a good approach in steep and rugged terrain. We’re hopeful for similar results this time.”


This project has been spearheaded by the Forest Service and WGFD’s Sheep Mountain Mule Deer Initiative. Additional assistance for the project was provided by Muley Fanatics Foundation and Albany County Weed and Pest.


"We are excited to partner with the Laramie Ranger District to address cheatgrass. This treatment will allow us to improve habitat conditions for mule deer, and for many other wildlife species that use the Squirrel Creek landscape," said Embere Hall, WGFD Wildlife Coordinator for the Laramie Region. 


Cheatgrass is a particularly aggressive invasive species that many agencies and landowners in the western United States are struggling to control. It is a prolific seed producer, thrives in disturbed areas and can displace native plants within grassland communities.


The ability to spray aerially on the Squirrel Creek Wildfire area is a result of the 2015 Record of Decision for Invasive Plant Management on the Medicine Bow-Routt National Forests and Thunder Basin National Grassland.


Specific questions about the project should be directed to Jackie Roaque (USFS), 307-745-2340 and Embere Hall (WGFD), 307-745-4046.