To improve native vegetation in prime bighorn sheep habitat, collaborators have spent 10 years spraying herbicide to knock back invasive cheatgrass in the Devil's Canyon area, east of Lovell, Wyoming.
Last fall, imazapic herbicide (Plateau) was sprayed from a helicopter on 233 acres of BLM-managed public land to combat cheatgrass expansion and improve habitat for bighorn sheep and other wildlife. Fall is when cheatgrass, a winter annual, germinates.
To date, 1,200 acres of public land have been treated in the Devil’s Canyon area, with the work expected to continue over the next several years.
“As we have seen in the Bighorn Basin, cheatgrass has the potential to increase and dominate plant communities by rapidly displacing native species,” said Bryan McKenzie, BLM range management specialist who coordinates the project for the Cody Field Office. “The goal of the treatment is to provide the slower growing native plants, many of which are tolerant of Plateau, with time to recover and compete.”
Long-term monitoring studies have been established in the project area and preliminary results show an upward trend in native vegetation.
“It takes partnerships like this to maintain productive habitat for bighorn sheep,” said Steve Kilpatrick, executive director of the Wyoming Wild Sheep Foundation. “The sheep need high-quality groceries to maintain body condition, ward off diseases, reproduce, have healthy, larger lambs and grow big horns.”
The Devil’s Canyon area on the west slope of the Bighorn Mountains contains important wildlife habitat for elk, deer and greater sage grouse, in addition to bighorn sheep. The productive and growing resident bighorn sheep herd is regularly used to augment bighorn sheep populations elsewhere in Wyoming.
BLM partnered with Big Horn County Weed and Pest, Wyoming Wild Sheep Foundation and Rocky Mountain Elk Foundation to fund application of the herbicide.