Residents and local officials in the Lake Tahoe area are mobilizing against a U.S. Forest Service plan to spray glyphosate and other herbicides on public forest land as part of post-wildfire restoration, citing cancer concerns and the risk of contamination to the lake’s watershed.
The Forest Service says the herbicide treatments are needed to clear brush and shrubs before replanting trees in areas damaged by the 2021 Caldor fire, which burned more than 200,000 acres. But community members, the Tahoe Regional Planning Agency (TRPA), and leaders of the Make America Healthy Again (Maha) movement are pushing back, arguing the risks to human health and the pristine alpine environment are too great.
Katherine Levy, a Lake Tahoe resident who recently moved back to the area for retirement, said she was “horrified” to learn of the plan. “I was horrified to find out what has been going on,” Levy said.
The Forest Service manages more than 156,000 acres (63,000 hectares) of national forest land within the Lake Tahoe basin. In March, agency officials said work to restore 11,700 acres (4,734 hectares) within the basin warranted “emergency” authorization. Within that project, the service estimated that 2,400 to 3,600 acres (971 to 1,457 hectares) “may be treated with herbicides to support reforestation,” according to a 2025 document laying out the plans.
The herbicides would not be sprayed from the air but from backpack sprayers to minimize damage to “non-target” native plants, the Forest Service said. The agency said it will work to reduce the risk of the pesticides getting into streams and other water bodies.
Roughly 75% of the lake’s watershed is within national forest land, and part of the area where spraying is proposed sits on mountains above the lake, with snow melt feeding into a tributary that leads directly into Lake Tahoe.
Cody Bass, mayor of South Lake Tahoe, said he was unaware glyphosate was still used on forest land. “I had no clue that glyphosate was still being used in the forest. It was kind of a shock to me that we know what we know about it and still use it on public lands,” Bass said.
Bass, who also sits on the 15-person governing board of the TRPA, said the agency strongly discourages the use of synthetic herbicides in the area. The TRPA sent a letter to the Forest Service’s Lake Tahoe basin management unit on May 27 asking for a meeting and urging the agency to minimize herbicide use “to the greatest extent feasible.”
The community only recently became aware of the plan after an article in the Mother Jones news outlet mentioned that up to 75,000 acres affected by the Caldor fire were targeted for glyphosate spraying, including areas near Lake Tahoe ski resorts. A follow-up article in late May reported that spraying had already taken place at one ski and snowboard resort south of Lake Tahoe within the Eldorado National Forest.
Kelly Ryerson, a Maha leader helping organize opposition, said the community is “shocked” by the plan. “The greater Tahoe community is shocked that the US Forest Service would even consider spraying glyphosate in its treasured, pristine forest, and is rapidly organizing to push back,” Ryerson said.
A town hall meeting was held on June 11 to strategize on how to fight the Forest Service plan. Some residents have called for action on social media, including in posts on Facebook groups such as Lake Tahoe Locals and Keep Tahoe Blue.
Glyphosate was introduced in the 1970s by Monsanto, and brands made with the chemical, such as Roundup, have long been popular with farmers, homeowners, and commercial landscapers. In 2015, World Health Organization (WHO) cancer experts classified the pesticide as “probably carcinogenic to humans.” The chemical is also linked to harms to animals, and federal regulators have found it could adversely affect over 90% of endangered species.
Bayer, which bought Monsanto in 2018, maintains that its glyphosate herbicides do not cause cancer. The EPA’s position is that glyphosate is “unlikely” to be carcinogenic.
The Forest Service lists glyphosate and four other herbicides in its plan for the continued restoration work, but most of the local outrage is over glyphosate and fears over its risks to both human and environmental health.
Robert Lorens, the Forest Service’s National Environmental Policy Act (NEPA) planner for the project, acknowledged community concerns. He pointed to information on the Forest Service website stating that each herbicide used is properly registered with regulators, has undergone a biological review, and has been determined to be the “best tool for achieving forest health or restoration.” The agency’s website also states that the Forest Service conducts a “rigorous and multidisciplinary assessment of each chemical” and its potential impacts.
Hannah Teter, who lives in the South Lake Tahoe area close to the area affected by the Caldor fire and works at a local wakesurfing charter company, said the plan is “deeply troubling.” “People come here from around the world because of its purity and natural beauty,” Teter said. “The idea of spraying thousands of gallons of herbicides across the Tahoe basin in an effort to dictate which species regrow after a natural wildfire is deeply troubling.”
The herbicide spraying on public forest land in Lake Tahoe is not unique. From 2017 to 2020, 938,732 pounds (425,803 kilograms) of pesticide products were applied on 1,467,944 cumulative acres (594,056 hectares) of federal Forest Service land throughout the U.S., according to federal data obtained by the Center for Biological Diversity (CBD).
Lori Ann Burd, director of the CBD’s environmental health program, said similar conflicts are likely to increase. “We expect there are going to be more and more of these spray projects. There is always some excuse that doesn’t make a ton of sense when you weigh that with the potential harms and risks,” Burd said.
This story was co-published with the New Lede, a journalism project of the Environmental Working Group.