the Wyoming Weed and Pest Council voted and approved to add downy brome, better known as cheatgrass, to the state’s Designated Noxious Weed List. The resolution, originally proposed by the Sublette County Weed & Pest District, now goes before the Wyoming Board of Agriculture. Pending final approval, cheatgrass is set to become the 32nd noxious weed on the state list, joining two other invasive annual grasses, ventenata and medusahead.
Cheatgrass is an invasive species that invades the Sagebrush Steppe and disturbed areas. While the grass is not new to the state, recent science and policy advances have improved the ability to manage it in Wyoming. Landscape-scale cheatgrass management programs, with a wide range of local, state and federal partners, are already taking place across Wyoming and its designation is expected to further support these programs. The Wyoming Weed and Pest Control Act defines designated species as detrimental to the general health or welfare of the state.
“Designation elevates awareness and recognizes that this species is no longer localized, but widespread,” stated Hale Redding, Weston County Weed and Pest District supervisor.
A recent University of Wyoming study found that cheatgrass impacts an estimated 5.3 million acres in Wyoming and an additional 10 million acres are estimated to have a presence of cheatgrass in low amounts. Agricultural losses on these impacted rangelands are estimated at $29 million and could reach $110 million if all suitable habitats become infested. Invasive annual grasses have gained a lot of attention in recent years due to their negative impacts on agriculture and wildlife habitat, specifically sage grouse. Recent wildfires have only amplified these concerns.
Various federal and state agencies and the Wyoming legislature have publicly recognized the need for action. In 2024, the Wyoming Legislature approved $9 million in funding to help support invasive annual grass treatment efforts. Districts are currently working with multiple partners to apply for this funding through the Wyoming Wildlife and Natural Resource Trust, which is administering the funding.
“We can estimate some losses to agriculture, but what we cannot account for is the cost of doing nothing,” Redding said. “Wyoming’s agriculture and natural resources are far too important to continue to let this invasive annual grass invade and become dominant. It is our job to protect Wyoming from invasive weeds and pests. There is no greater threat to Wyoming than cheatgrass.”
The current Designated Noxious Weed List, along with tips and procedures for reporting invasive species, can be found at wyoweed.org/identify-weeds/
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WY Weed and Pest Council