Help Us Fully Ban M-44 “Cyanide Bombs”

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Will it take the death of a child to fully ban M-44s, the indiscriminate poison land mines lurking in our great outdoors in at least 10 states? We fear it might. These cyanide-dispersing devices used by government agents to kill livestock predators have already poisoned people and killed countless dogs and nontarget wildlife. In 2023-24 alone M-44s killed over 10,000 animals. Since M-44s cannot be used safely, they are a public safety menace, and we have initiated and led national and state-level efforts to ban them since 1990. Significant progress has been made, yet now, in 2025, it is all at risk.

Heart-Grabbing Documentary Shows Real World Impact of M-44s

Screenshot from M-44 film, Lethal Control

This poignant, independent documentary features some of the people we’ve worked with over the years whose lives have been forever changed by M-44 “cyanide bombs.” Once you meet them in this film, you’ll truly understand why M-44s must be banned. Watch film | Read stories about other victims

Key Happenings: 

Press conference from one of our trips to the U.S. Capitol with the Mansfield family of Pocatello, ID, urging passage of Canyon’s Law, a federal bill to ban M-44 ‘cyanide bombs.’ Photo credit: Jenifer Morris Photography

Overview

In our decades-long work toward a nationwide ban on deadly M-44 cyanide devices (aka “cyanide bombs”), a turning point occured when we traveled to Washington, D.C., with the Mansfield family of Pocatello, Idaho (pictured above). The Mansfields lost their dog and almost lost their son on March 16, 2017 to an M-44 device set on a hill behind their back yard. Due to the shocking reality of their experience, and their determination to not just be victims but to create change, the Mansfield’s were very effective in our 2017 and 2019 trips to urge members of Congress to wake up to the need for federal legislation.

As of June 2025 M-44s are confirmed as still being used by the government for predator control in 10 states. They are allowed statewide in Colorado, Montana, Nebraska, Nevada, New Mexico, North Dakota, Oklahoma, Texas, West Virginia and Wyoming. The EPA also authorizes M-44 use by state agencies in Montana, New Mexico, South Dakota, Texas, and Wyoming. We continue to work toward a nationwide ban, while also pushing ahead on a state and local level to encourage local jurisdictions to lead the way. Progress is being made, as detailed below.

Canyon’s Law: Two Bills to Ban M-44s on Public Lands Introduced in Congress

June 2025 – We’re pleased to announce that two bills to ban M-44s on all public lands were introduced in Congress on June 26, 2025. Nicknamed “Canyon’s Law” in honor of Canyon Mansfield, these common-sense, tax-saving, nonpartisan bills should be supported without resistance as an essential public safety measure by all elected officials. Read our press release | Help get these bills passed

U.S. House Bill

U.S. Senate Bill

How You Can Help: Key Actions to Fully Ban M-44s on Public Lands

SUPPORT CANYON’S LAW: You can help ban M-44 “cyanide bombs” on all public lands by urging your U.S. Senators and Representatives to support Canyon’s Law, so nicknamed in honor of Canyon Mansfield. You can call them via the Capitol Switchboard at (202) 224-3121 or copy/paste the statement below into an email using contact info at links below:

Dear _________,

Please support Canyon’s Law (H.R. 4180/S. 2179), the bill to ban M-44 “cyanide bombs” on public lands. It is common-sense, tax-saving, nonpartisan legislation deserving support as an essential public safety measure by all elected officials.

M-44 sodium cyanide-dispersing devices are used by USDA wildlife agents for controlling predators like coyotes and foxes. They are scientifically shown to be indiscriminate and counter-productive and can be replaced with a number of effective nonlethal methods. Not only do M-44s kill nontarget wildlife and endangered species, but they have killed countless family dogs, severely injured dozens of people, and permanently disabled one man and contributed to his death. Experts in the field affirm it is only a matter of time before an M-44 kills a child.

In the 2017 Pocatello, Idaho incident that received worldwide attention, 14-year-old Canyon Mansfield touched what he thought was a sprinkler head while taking a customary walk near his house. It was an M-44 device and the explosive cyanide cloud that erupted killed his dog in front of him. Canyon is only believed to have missed death due to wind direction. His case led to the naming of this bill as Canyon’s Law.

I believe the federal government has no justification for attempting to manage native predators with a device that can never be used safely. As you can see, most victims of these devices cannot even read warning signs. Please support Canyon’s Law to ban M-44s on public lands to make them safer for all.

Thank you very much for you consideration of this important bill.

Sincerely,

[Your name]

OTHER WAYS TO HELP: In addition to contacting key government leaders, we encourage you to share this webpage and spread the word to everyone you know who cares about pets, kids, wildlife, and safety in the great outdoors, urging them to take the same actions.

You can also further our efforts by making a donation to support our work, which includes raising public awareness, coordinating campaigns with other interested environmental and animal welfare organizations, and educating elected officials on why M-44s are a public safety menace and banning them is a nonpartisan issue. Any donation amount helps and is greatly appreciated. DONATE TODAY

Pushing for Public Lands Bans, Regardless of Federal Bill Status

We’ve long worked towards public lands bans, regardless of the status of federal legislation. One of the most exciting developments happened during a House Subcommittee hearing on Canyon’s Law held July 21, 2022 before House Natural Resources Subcommittee on Water, Oceans and Wildlife (WOW). Part of the testimony for the hearing included a statement from the Dept. of the Interior indicating they were open to the ban of M-44s on lands they control. We were thrilled to see this and worked to leverage it by calling for a ban on BLM lands. Here are key hearing links:

On Oct. 6, 2022 Rep. Peter DeFazio (D-Oreg) and Committee Chair Jared Huffman (D-Cal) followed up with a letter to Interior Secretary Deb Haaland requesting a ban on M-44s on lands they control (Bureau of Land Management), regardless of the status of Canyon’s Law. On June 29, 2023 over 70 conservation groups joined us in urging the Interior Department to ban cyanide bombs on public lands. Press release | Official APA petition

On Nov. 22, 2023 we were absolutely thrilled to see the Interior Department ban M-44s on 245 million acres of public lands, all lands managed by the BLM. Victory Spotlight | Our press release | Rep. Jared Huffman’s press release

On the state level bans on M-44 use on public lands happened temporarily in Colorado and Texas. Colorado banned use of M-44s on public lands in 2017, pending further study, and Wyoming banned M-44s on 10 million acres public lands in 2019, pending results of a lawsuit against USDA Wildlife Services which required a new EIS. Unfortunately, these temporary state bans did not stick.

On October 23, 2024 we submitted an official APA petition to the U.S. Forest Service and USDA, asking for an official ban on all 193,000,000 acres of national forest lands. Press Release | How you can help

Our work continues. M-44 use is utterly unacceptable. And we will not back down.

VICTORY SPOTLIGHTS: “Cyanide Bombs” Banned on 245 Million Acres of Public Lands!

Photo of Bureau of Land Management (BLM) sign

We were thrilled to announce on Nov. 22, 2023 that the U.S. Interior Department has banned the use of M-44 devices, commonly known as “cyanide bombs,” on lands administered by the Bureau of Land Managment (BLM). This includes over 245 million acres, roughly a tenth of the nation’s land mass. It means countless thousands of wild animals will not be killed on BLM lands, including endangered species. It also means people can feel free to walk their dogs on these public lands and not risk death or poisoning. This win is historic. It can and should lead to bans on all public lands, and ultimately a ban on all M-44 devices.  Our work continues to this end.

Idaho bans use of M-44s, pending full EIS; Mansfield family wins precedent-setting legal battle

After a long, high profile fight, we’re pleased to announce a strikingly good court decision in March 2020 banned M-44s statewide in Idaho. It’s a win for a great outdoors free of “cyanide bombs” and we are proud to have been a plaintiff in this landmark case. The decision locks in Idaho’s tentative moratorium on M-44s, until the agency completes a full Environmental Impact Statement (EIS), which will take a minimum of four years, and is unlikely to happen.

August 2020 brought another big Idaho win via the Mansfield family’s lawsuit against USDA Wildlife Services. Their case–arising from the 2017 wrongful killing of their dog Kasey and poisoning/potential killing of their son Canyon with an illegally placed M-44 on a hill behind their home–was about principle, not money. Due to their perseverance and determination, the Mansfield family achieved a first–they prevailed in holding the government accountable for one of countless incidents in which indiscriminate, poisonous land mines, planted in our great outdoors for “predator control,” have killed wild animals, dogs, and potentially a child. Wildlife Services admitted it was negligent. This sets a very important precedent indeed.

Oregon’s statewide M-44 ban went into effect in 2020

https://www.predatordefense.org/m44s.htm

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