By Morgan Tuss
For many in Montana, rivers and lakes are more than just scenic backdrops. They are a source of food, recreation, and identity. Families fish for dinner, anglers travel from across the country to cast a line, and communities rely on these waterways as a cornerstone of life in Big Sky Country. But a growing body of evidence now shows that something deeply troubling is contaminating these waters: PFAS, a class of so-called “forever chemicals.”
Despite the seriousness of this issue, there is increasing concern that the public has not been adequately warned. Environmental concerns can have lasting implications for families and future generations, making thoughtful planning with a Great Falls, MT estate planning lawyer an important part of protecting your assets, property, and legacy.
Recent state studies have confirmed PFAS contamination in fish across multiple major Montana waterways, including the Missouri River, Clark Fork River, East Gallatin River, and Fort Peck Reservoir. Testing has detected these chemicals in popular species such as trout, walleye, and northern pike, which are fish that many Montanans regularly catch and eat. Even more concerning, PFAS were found at particularly high levels in larger fish due to bioaccumulation, the process by which toxins build up and intensify as they move up the food chain.
In some cases, reported concentrations reached levels that experts say are thousands of times higher than what is considered safe for human consumption. These findings make it clear: PFAS contamination is not limited to isolated locations. It is present in some of the state’s most iconic and heavily used fisheries.
PFAS (per- and polyfluoroalkyl substances) are synthetic chemicals used since the 1940s in products like firefighting foam, nonstick cookware, waterproof fabrics, and food packaging. They are often called “forever chemicals” because they break down extremely slowly, persisting in water, soil, animals, and even the human body for decades or longer.
Scientific research has linked PFAS exposure to serious health concerns, including:
- Certain cancers (kidney and testicular)
- Immune system suppression
- Developmental issues in children
- Hormonal and reproductive problems
Because these chemicals accumulate over time, even low-level exposure through frequent fish consumption can become a long-term health risk.
In response to the findings, Montana agencies issued updated fish consumption advisories in 2026, warning residents to limit or avoid eating fish from certain waters. There are now at least 21 new or updated consumption advisories statewide. These advisories include recommendations such as:
- Avoiding large walleye and trout in certain reservoirs
- Limiting how many fish meals can be consumed per month
- Advising stricter limits for women and children
These advisories are not regulations. They are simply recommendations.
Perhaps the most troubling aspect of the PFAS issue in Montana is not just the contamination, but how long it took to reach the public. A key state report identifying high PFAS levels in fish was completed in 2023 but was not publicly released until 2026. Investigations have suggested that state officials were aware of the contamination for more than a year before the information became widely available. This delay has raised serious questions about transparency and public health priorities. During that time, many Montanans continued fishing and consuming fish without knowledge of the potential risks.
Fishing is not just a pastime in Montana. It is often a practical source of food, especially in rural and lower-income communities. Many families depend on locally caught fish as part of their regular diet. Yet without clear and proactive warnings, people may unknowingly expose themselves to contaminants that accumulate in their bodies over time. PFAS contamination also threatens tourism and the outdoor economy, which depend heavily on the perception of Montana as a pristine natural environment.
While the state has taken steps to issue advisories, several factors suggest the public still isn’t receiving adequate warning:
- Limited visibility: Advisories are often posted online or in technical documents, not widely broadcast.
- Complex guidance: Consumption limits based on fish size, species, and location can be confusing.
- Delayed communication: The lag between discovery and disclosure undermines trust and awareness.
Additionally, researchers acknowledge that current sampling only covers a small portion of Montana’s vast waterways, meaning contamination could be more widespread than currently documented. The PFAS issue in Montana highlights a broader challenge facing communities nationwide: how to manage emerging contaminants that are widespread, persistent, and not yet fully understood.
Experts and advocates argue that more robust public communication is essential, including:
- Clear, highly visible warnings at fishing access points
- Simplified guidance for everyday fish consumers
- Expanded testing across more waterways
- Faster release of environmental health data
At its core, the issue is about informed choice. Montanans cannot protect their health if they do not know the risks.
PFAS contamination in Montana’s rivers and fish is no longer a hypothetical concern. It is a documented reality. The chemicals are present, the health risks are real, and the exposure pathways are part of everyday life for many residents.
Yet awareness still lags behind the science. Without stronger warnings, clearer communication, and greater transparency, many Montanans may continue to unknowingly put themselves and their families at risk. In a state defined by its natural resources, ensuring the safety of those resources, and the people who depend on them, should be a top priority. Silverman Law Office, PLLC helps individuals, families, and businesses stay informed about environmental, property, and regulatory issues that may affect their health, land, and long-term interests throughout Montana.
Morgan E. Tuss is an attorney with Silverman Law Office, PLLC. She holds a dual LL.M. in tax law and estate planning.
