The grassroots campaign against the use of herbicides in a Tomales Bay State Park forest health and wildfire-mitigation plan is gaining force as Assemblyman Damon Connolly, Supervisor Dennis Rodoni, the Inverness Association, and the Environmental Action Committee of West Marin join the chorus of opposition.
Meanwhile, the Tomales Bay Foundation, whose leaders expressed support for the plan last month, is evaluating public outcry over its position, and the number of signatures on an online petition has broken 2,000.
“Harmful chemicals found within pesticides and herbicides can persist for years in the environment and numerous studies have found that they are incredibly harmful to human health and wildlife,” Mr. Connolly wrote in a July 14 letter to Armando Quintero, the director of California State Parks.
Herbicides are one of several tools included in the department’s Tomales Bay State Park Forest Health and Wildfire Resilience Project. The plan aims to restore the 2,400-acre park’s bishop pine forest by thinning trees and reducing invasive species, which outcompete native species and create layers of flammable vegetation.
Under the plan, herbicides could be applied in several areas, including near homes in Inverness, totaling less than six acres. They would be used in coordination with manual removal, mechanical excavation, and prescribed burns.
Mr. Connolly urged the department to utilize these other means to accomplish the project’s goals and to consider ceasing herbicide use throughout California.
In a statement sent to the Light on Tuesday, Mr. Rodoni urged state park officials to refrain from using herbicides and said he would press them for more information about their plans.
“I support the goals of restoring native habitat, improving forest health, and reducing invasive species,” he wrote. “At the same time, I do not support application of herbicides in the Tomales Bay watershed.”
The forest plan, about seven years in the making, was approved by the California Coastal Commission in 2024. But its implementation has not begun: It’s tied up in a lawsuit brought by two environmental groups who argued the project underwent inadequate environmental review and would imperil the ecosystem rather than protect it.
The issue gained traction recently after Kristin Lawless, an Inverness resident who writes a Substack column, read through the plan and discovered the section allowing the use of glyphosate, a toxic weedkiller sold widely under the brand name Roundup.
She posted an impassioned article about the issue, while her friend, Inverness artist Cole Zlata, drafted the Change.org petition and painted the “No poison in our watershed” signs that quickly cropped up around town.
Their campaign hasn’t taken long to produce results. Just days before Mr. Connolly sent his missive, the Inverness Association wrote a letter expressing concern to Mr. Quintero.
“We support the idea of restoration at the park,” wrote the association’s board president, Jerry Meral. “But we urge you to not include the use of herbicides in your plan.”
The letter pointed out that the state park encompasses much of the watershed that serves the town as drinking water and drains into Tomales Bay, which is already classified by the state as an impaired waterway.
“Even though we understand that the department’s use of herbicides would be in accordance with state and federal regulations, our residents feel strongly that there should be no use of herbicides in watersheds that provide our drinking water,” it said.
The plan states that herbicides would be an option of last resort and includes many restrictions on their use. They would be applied by ground-based methods, with backpack sprayers or by hand to cut stumps, and they would be barred near streams that support fish, drinking water, or other aquatic life. Adjacent no-spray zones would range from 50 to 150 feet, and their use would also be prohibited within 50 feet of endangered or threatened plant species.
When the forest plan went before the coastal commission two years ago, various environmental groups weighed in against it, but the Environmental Action Committee of West Marin expressed support. At the time, the group said it endorsed herbicide use only when no other solutions were practical and invasives posed an “insurmountable challenge.”
But on June 24, after the local protests erupted, the E.A.C. updated its webpage, saying it opposed the use of any herbicides, including glyphosate, in the forest plan.
“The International Agency for Research on Cancer lists glyphosate as ‘probably carcinogenic to humans,’ and California’s Proposition 65 also lists it as a carcinogen,” it wrote. “Additionally, in 2025, one of the hallmark studies that claimed there was no evidence that glyphosate caused cancer was retracted due to ethical concerns about its authorship (Monsanto employees may have contributed to its writing) and the validity of the findings.”
The E.A.C. pointed out that multiple Marin municipalities and agencies have either banned or discontinued the use of glyphosate on public lands, including the county parks department and the cities of Novato, San Rafael, Larkspur, and Mill Valley.
State Parks developed the Tomales Bay project after commissioning a survey by Inverness forester Tom Gaman that raised alarm about the health of the forest, home to the largest bishop pine reserve on earth. Many of the trees are old and dying, contributing to a deep and combustible understory.
Last month, Mr. Gaman, who chairs the Tomales Bay Foundation board, and two other board members wrote a letter to the Light that defended the forest plan.
“In our view, the state park’s project is selective and judicious,” they wrote. “Glyphosate will be applied directly to or sprayed on tree stumps and vegetation on less than six acres. It is unlikely to spread into the environs and waters using these techniques.”
After the publication of their letter, a foundation advisory board member, Rebecca Smith-Bindman, who is a professor of biostatistics and epidemiology at the University of California, San Francisco, wrote a stinging dissent.
Protecting the bishop pine forest from disease and wildfire is a pressing need, she said, but chemicals are not the solution. “The evidence has convinced me that glyphosate causes cancer, and I believe there is no place for it in our watershed,” she wrote.
Mr. Gaman declined to comment on the latest developments in the anti-herbicide campaign, but board member Woody Elliott said the foundation is taking stock of the public outpouring.
“I have no comment at this time pending the conclusion of the board’s deliberations,” Mr. Elliott said.
Responding to questions from the Light last month, state parks officials defended the agency’s vegetation management practices, without mentioning herbicides.
“State Parks carefully considers and strategically deploys a variety of treatment options to manage vegetation,” it stated, adding that it calibrates its approach to the unique environmental characteristics of each park in its sprawling system.
This week, department spokesman Marty Greenstein told the Light that the department has received a variety of correspondence about the plan, but he declined to respond to Mr. Connolly’s letter.
“To be clear, State Parks currently is not using herbicide in Tomales Bay State Park and does not have any immediate plans to do so,” Mr. Greenstein said.
For her part, Ms. Lawless is surprised and pleased that her Substack post has resonated with so many people. A Philadelphia native, she spent her teenage years in Southern California and later graduated from U.C. Santa Cruz. She moved to West Marin a few years ago after launching her career as a writer in New York, where she participated in the Occupy Wall Street movement and helmed a group that grew out of it called Occupy Big Food. Her book “Formerly Known as Food” examines the health impacts of chemicals in the food supply.
“A lot of times, writing feels like a solo endeavor,” Ms. Lawless said. “Sometimes it feels like you’re yelling into the void. It’s rewarding that people are listening and want to do something about this. If we can get this stopped locally, that would be such a big win and a good model for other communities.”
Mr. Connolly sent his letter to state parks after Ms. Zlata presented him with a policy brief that she composed with Ms. Lawless. She also presented the brief to a staffer for State Sen. Mike McGuire but has yet to hear back.
A Point Reyes Station resident with long family ties to West Marin, Ms. Zlata worked as a public health consultant for many years, focusing on women’s health in Africa. A graduate of U.C. Santa Cruz, she now works full time as a painter.
“We still haven’t gotten what we need to happen, which is for State Parks to actually remove herbicides from its plan,” she said. “That’s the goal.”
Support for the activists is strong but not universal. Some have objected to the “No Poison in Our Watershed” signs as a form of visual pollution, several signs have been removed or vandalized, and a new one has popped up with a snide retort: “No Ants in Our Pants.”