Lake Tahoe residents ‘horrified’ by plans to spray cancer-linked glyphosate in public lands

Katherine Levy remembers a childhood deeply rooted in the natural offerings of Lake Tahoe – water-skiing in the summer and working as ski instructor on the surrounding snow-covered mountains during winter months.

She recently moved back to live out her retirement along the lake’s north shore. But she doesn’t like what she has found upon her return: a US government plan to spray multiple types of herbicides, including the cancer-linked glyphosate weed killer – within national forest property that abuts the community’s cherished lake.

“I was horrified to find out what has been going on,” Levy said.

Levy is among a number of Lake Tahoe-area residents and officials who are fighting to block or alter the US Forest Service project, which is aimed at restoration of areas damaged by the 2021 Caldor fire.

The wildfire burned through more than 200,000 acres, including land in and around the Lake Tahoe basin. The Forest Service manages more than 156,000 acres (63,000 hectares) of national forest land within that basin.

The agency’s restoration plan states that the use of glyphosate and other herbicides is needed to help clear areas of shrubs, brush, and other vegetation before new tree plantings and to manage vegetation that might interfere with the growth of the trees after planting.

The herbicides would not be sprayed from the air, but from backpack sprayers to try to minimize damage to “non-target” native plants, and the Forest Service has said it will work to reduce the risk of the pesticides getting into streams and other water bodies. Locals remain concerned and a town hall meeting was held on 11 June 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.

There are similar fights over forestry pesticide use playing out across the US, but the Lake Tahoe issue has drawn the attention of leaders with the Make America Healthy Again (Maha) movement, who have been lobbying the US Environmental Protection Agency (EPA) to ban or severely restrict glyphosate use.

“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,” said Maha leader Kelly Ryerson, who is helping organize opposition.

Glyphosate was introduced in the 1970s by Monsanto, and brands made with the chemical, such as Roundup, have long been popular with farmers as well as homeowners and commercial landscapers. But 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.

The German multinational Bayer bought Monsanto in 2018 and maintains that its glyphosate herbicides do not cause cancer. The Environmental Protection Agency (EPA) position is that glyphosate is “unlikely” to be carcinogenic.

Worried about the water

Lake Tahoe has long been a popular tourist destination, recognized as the largest alpine lake in North America and relatively pristine. It sits in the Sierra Nevada mountain range, straddling the border of California and Nevada. Area residents are spread among 12 towns and two mountain villages.

Roughly 75% of the lake’s watershed is within national forest land and part of the area where spraying is proposed to take place sits on mountains above the lake, with snow melt feeding into a tributary leading directly into Lake Tahoe.

“It is a major concern for all of us,” said Cody Bass, mayor of South Lake Tahoe. “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, who is also a local business owner, sits on the 15-person governing board of the Tahoe regional planning agency (TRPA). The TRPA strongly discourages the use of synthetic herbicides in the area and Bass is now asking the board to prohibit the chemicals.

The TRPA sent a letter to the Forest Service’s Lake Tahoe basin management unit on 27 May asking for a meeting with Forest Service officials on the matter. The letter notes that the TRPA and water-quality officials want to minimize herbicide use “to the greatest extent feasible”.

View image in fullscreen Forest Service workers reforest the land near the Sierra-at-Tahoe ski resort in California after the Caldor fire, on 12 May 2026. Photograph: Andrew Avitt/U.S. Forest Service

Though Forest Service plans for the larger restoration project have been in motion for well over a year, the community only recently became aware of the work 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. The plans include areas near Lake Tahoe ski resorts, Mother Jones reported.

A follow-up article by the outlet revealed in late May that spraying had taken place at one of the area’s ski and snowboard resorts south of Lake Tahoe within the Eldorado national forest.

The herbicide spraying on public forest land in Lake Tahoe is not unique. From 2017 to 2020, 938,732lbs (425,803kg) of pesticide products were applied on 1,467,944 cumulative acres (594,056 hectares) of federal Forest Service land throughout the US, according to federal data obtained by the Center for Biological Diversity (CBD).

Lori Ann Burd, director of the CBD’s environmental health program, said: “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.”

‘Emergency’ authorization

In March, Forest Service officials said work to restore 11,700 acres (4,734 hectares) within the Lake Tahoe basin warranted “emergency” authorization. Within the project, the service estimated that 2,400-3,600 acres (971-1,457 hectares) “may be treated with herbicides to support reforestation”.

“Forest restoration involves targeted actions to facilitate post-fire recovery of the forested landscape; enhance resilience to wildfire, insects and disease; and support wildlife species that depend on healthy forest habitats,” the Forest Service stated in a 2025 document laying out its plans.

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.

When asked about the local opposition, 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.

Some residents remain concerned.

“People come here from around the world because of its purity and natural beauty,” said 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.

“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,” Teter said.

This story is co-published with the New Lede, a journalism project of the Environmental Working Group