The Bureau of Land Management is spraying herbicides from helicopters over federal lands in Klamath and Lake Counties through the end of the year, targeting invasive grasses that fuel wildfires. The treatment spans 12,585 acres and involves chemicals such as glyphosate, which is currently under review by the U.S. Environmental Protection Agency.
The bureau’s Lakeview District Office has used aerial herbicides for a decade, as other methods weren’t keeping up with the growth of invasive species.
Cheatgrass, medusahead rye and North Africa grass are the most common invasive plants in the area. These grasses often spread after native species have gone dormant, hogging nutrients needed by native plants during their growing season.
Oliver Liu, invasive annual grass specialist at the BLM Lakeview District Office, monitors which areas in the district are most heavily infested with invasive grasses and need treatment. This year, much of the targeted land includes areas burned by wildfires in the past year or two.
“We presume that there’ll be a heavy invasive grass infestation following any big wildfire events,” Liu said.
Four areas burnt by 2024 wildfires — the Road 157 Fire, the Bowman Well Fire, the Tucker Hill Fire and the Warner Peak Fire — are scheduled for treatment this year.
The Lakeview District plans to use two herbicides: imazapic and glyphosate. Imazapic, sold under the trade name Plateau, is primarily used to prevent invasive seeds from sprouting. Glyphosate, commercially known as Roundup, is used after invasive plants have emerged and are competing with native vegetation.
The EPA said in 2020 that glyphosate is safe for human health and unlikely to cause cancer if used correctly. But two years later, the 9th U.S. Circuit Court of Appeals threw out that conclusion, saying the agency didn’t have enough evidence to support it.
Separately, the International Agency for Research on Cancer, a branch of the World Health Organization, labeled glyphosate as “probably carcinogenic to humans” in 2015. While the agency acknowledged that there was limited evidence in people, it based its assessment on stronger evidence from animal studies.
The EPA expects to complete a review of glyphosate’s safety in 2026. Until then, it stands by its original assessment that the chemical is not a carcinogen for humans.
The Lakeview District didn’t use glyphosate in its aerial spraying programs in 2023 or 2024. Liu said the office hasn’t been told by BLM to stop using it, but said that, under agency guidelines, it’s considered safe to re-enter treated areas once the herbicide has dried.
Glyphosate, because it targets growing plants, can pose a risk to native plants if not timed correctly. That’s why spraying in the fall and winter is critical, Liu said.
“We’re usually outside of that growing season of most of the natives that we’re trying to avoid,” he said.
The locations where herbicides are being sprayed by the Lakeview District can be found on the Bureau of Land Management website.
