SHERIDAN — Conservationists discovered two invasive grasses in the Sheridan County area in 2016. Medusahead and Ventenata present a large problem for vegetation in the Great Plains Eco-region, but Sheridan residents have worked diligently to eliminate the invaders.

Registration for the second Wyoming “Medusa-nata” tour and educational day quickly met capacity, and the event will run from 8:30 a.m. to 4 p.m. Tuesday. Sheridan County Weed and Pest supervisor Luke Sander said this year will be more involved than the first, stopping at a few more sites and seeing progress in the fight against the invasive grasses.

“We put some different test plots up last year with different chemical mixes to see how the grasses responded to those,” Sander said. “So that’s going to be our main stop, looking at all those different chemicals and see how the grasses responded.”

The region uses one main chemical to remove Medusahead and Ventenata, and conservationists are working to receive an emergency exemption for Wyoming to use a new chemical. The current chemical holds the invasive grasses off for just a year or two; Sander hopes the new chemical will work long term. Because the two invasive grasses have never been found in Wyoming nor the Great Plains Eco-region before the 2016 discovery, conservationists in the area are looking to the western states for help in eradicating the pests.

“We don’t know how it’ll respond in this climate and these soils,” Sander said. “It’s kind of a big deal.”

Representatives from the University of Idaho and Utah State University will present at the field tour. Washington suffered greatly from the invasive grasses in 2016, and Wyoming looks to the state for statistical predictions as well as any possible solutions.

“There’s some data that suggests that between 70 and 80 percent of forage could be lost if these get a hold,” Sander said. “In Washington, they’ve seen 70 percent of grazing land (overcome by the invasive grasses.)”

In addition to grazing land, the invasive grasses strangle flora, promote dangerous wildfires, diminish diversity and reduce wildlife habitats, according to the Sheridan County Weed and Pest website. The grasses overrun native vegetation because they germinate early in the fall and deplete soil nutrients and moisture.

The tour itself includes lectures from university representatives, a visit by bus to the Early Creek Medusahead site, viewing of treated and non-treated test plots and an aerial herbicide application demonstration.

“They’ll be able to see what was found to be the worst patch of Medusahead around eastern Sheridan County and is untreated,” Sheridan County district conservationist Andrew Cassiday said.

Representatives will be in attendance from the Department of Interior, U.S. Forest Service, Bureau of Land Management, Fish and Wildlife, Department of Agriculture and the Wyoming Game and Fish Department.

“I think it’ll be a good opportunity to see the fields, see some treatment, tests and what’s promising,” Cassiday said.

While Wyoming looks to western states making headway in the eradication of these two invasive grasses, Sheridan County continues its own battle within the region.