A Bridger-Teton National Forest hillside in the Boulder Ridge area north of Pinedale has become dominated by cheatgrass. Forest officials have sought authorization to combat the non-native grass with aerial spraying of herbicides.

A fast-spreading exotic grass will be knocked back on forestland around Jackson Hole using crop-dusting-style aerial techniques if a plan on the table flies.

The Bridger-Teton National Forest’s invasive plant management plans do not authorize aerial spraying of cheatgrass and other invasive plant species. But forest officials asked for approval last week to authorize the technique by releasing an environmental impact statement that proposes using crop-dusting-style techniques to treat and ideally kill thousands of acres of cheatgrass annually over the next 15 years.

“We could cover with a helicopter on one of these south-facing slopes within a half-hour what it takes six or eight weeks to run with horseback and backpack crews,” Chad Hayward, a Bridger-Teton natural resources manager, told the Jackson Hole News&Guide in April 2018.

The “preferred alternative,” or proposal detailed in the Bridger-Teton’s EIS, calls for annually treating 10,000 to 15,000 acres of the 3.4 million-acre forest using both ground and aerial methods for the next 15 years. Parts of the landscape that would be sprayed include big-game winter range, sage grouse habitat, areas burned and thinned to reduce wildfire fuels, fire scars, roads and trails, and areas where beetle-killed forests have given way to invasive plants. Only EPA-approved chemicals would be used, the document says.

Other national forests in the American West that are overrun by cheatgrass have for years aerially sprayed cheatgrass, which is native to Eurasia and northern Africa. The Bridger-Teton never sought the authorization, partly because early Forest Service botanists doubted the species could proliferate in high, snowy northwestern Wyoming forests.

“Some very good ecologists at the time said, ‘You know what, we’re never going to have a problem here,’” Hayward said. “They thought that native grasses and plants are going to outcompete it and it’s going to go away.”

The passage of time has proven that resilient cheatgrass is capable of overtaking native vegetation here, even well above 6,000 feet in elevation.

The best estimate is that non-native plants of all species live on 75,000 acres on the Bridger-Teton, around 2% of the overall land area. Of that, cheatgrass accounts for around 25,000 acres, but it is gaining ground by as much as 20 percent per year and has infested slopes from Jackson Hole south to the tip of the Wind River Range. The Winds’ South Pass area is hardest hit, but smaller-scale infestations are widespread.

Jackson residents can find cheatgrass as close as the hillsides that rise over town: Crystal and East Gros Ventre buttes both have visible swaths of the quick-curing grass, which turns brown earlier in the year than native grasses.

Twenty-nine invasive species are addressed in the proposed management plan, including plants like musk and Canada thistles, houndstongue and yellow toadflax. But cheatgrass, the document makes clear, is fueling the desire to update plans to include aerial spraying.

“Because aerial application has not been available as a treatment method, Forest Service land managers have not participated in cooperative weed management efforts to treat infestations that spread across Forest, BLM, State and private land,” the planning document states.

Cheatgrass removal projects have been abandoned, and untreated areas have been left adjacent to sprayed areas, creating a weed source that spreads cheatgrass seeds and reinfests areas where state, county and private dollars have already been spent.

Comments on the Bridger-Teton’s plan are due May 20. They can be emailed to with “Invasive Plant Management” in the subject line.

Contact Mike Koshmrl at 732-7067 or

Mike has reported on the Greater Yellowstone Ecosystem's wildlife, wildlands and the agencies that manage them for 7 years. A native Minnesotan, he arrived in the West to study environmental journalism at the University of Colorado.

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