When Barbara Miller was in elementary school, she covered her face while walking to class. “It hurt so bad to breathe. Your neck, your throat, your eyes,” Miller said. Doors that led to a breezeway got jammed with kids “[backing] up like cattle,” Miller said, because no one wanted to exit the school and enter the smog.
Smokestacks from the nearby Bunker Hill Smelting Complex, a facility that separated silver from impurities, pumped sulfuric acid and lead oxide, byproducts of silver refining, into the surrounding communities. The Bunker Hill Smelting Complex was the largest smelting facility in the world at the time of its construction in 1917. In the 1970s, irresponsible management of the smelter caused dangerously high blood lead levels among children in the Coeur d’Alene Mountains of Northern Idaho, a region also known as the Silver Valley.
Since the 1980s, when the Environmental Protection Agency (EPA) added Bunker Hill to the National Priorities List (NPL), a list of communities targeted for hazardous waste mitigation, otherwise known as Superfund sites, the cleanup process has been fraught with disagreement over the future of the region. Many Silver Valley residents bear the burden of lead poisoning in the form of chronic ailments.
And although blood lead levels have improved since the 1980s, contamination remains a concern among residents and public health officials. The future of the Silver Valley still hangs in the balance as the Bunker Hill Mining Corporation seeks to bring a more modern (and supposedly safer) version of mining to the region.
A Century of Mining in the Idaho Panhandle
In 1884, carpenter and prospector Noah S. Kellogg went gold hunting on the Coeur d’Alene River in North Idaho. Kellogg never struck gold – he showed up to the rush too late – but he did stake a claim in an orebody that eventually became the site of the Bunker Hill Mine, which opened in the fall of 1885 and operated for more than a century.
At Bunker Hill, about five miles south of Smelterville, Idaho, small-scale mining quickly turned industrial, culminating in the creation of a collection of mines in the region that came to be known as the Coeur d’Alene Mining District. By the time operations ceased in 1981, the Bunker Hill Mine had produced 35 million tons of ore concentrate and extracted 165 million ounces of silver.
Mining in Idaho’s Silver Valley goes back to the 1880s. The Bunker Hill Mine extracted 165 million ounces of silver in the century-long history of its operation. (Photo by Ilana Newman)
The tailings, or mine waste, from this industrial powerhouse were dumped into nearby streams and rivers, the standard method of disposal at the time. When mining companies in the Silver Valley stopped dumping waste into the waterways in 1968, an estimated 62 million tons of tailings had already been unloaded into the South Fork of the Coeur d’Alene River. Almost one million tons of that waste contained lead. When the Coeur d’Alene River flooded nearly every spring, lead-contaminated water poured into yards, streets, and buildings.
In 1973, a catastrophic fire burned through the smelter facility’s filtration system, exacerbating the pollution problem. In an effort to take advantage of high silver prices, company officials kept the mining running despite the facility’s need for maintenance and repairs. The facility discharged nearly 35 tons of lead per month into the town that year, creating one of the largest lead-poisoning events in the nation’s history. In 1974, 99% of the children who lived within a mile of the smelter facility had blood lead levels higher than 40 micrograms per deciliter, with an average around 67.4 micrograms per deciliter, more than 85 times higher than the reference level at the time.
Betty Belisle is a member of the Silver Valley Community Resource Center. She grew up in Idaho’s Silver Valley. (Photo by Ilana Newman)
Today, the Centers for Disease Control and Prevention (CDC) considers any lead in the blood unsafe, but uses a threshold of 3.5 micrograms per deciliter to determine who receives interventions. Anything higher than that threshold requires follow up from public health professionals to help eliminate the source of exposure.
The Bunker Hill Smelting Complex was dismantled in the 1990s, but concerns over lead contamination persist among some Silver Valley residents.
Betty Belisle was in elementary school in the 1970s, when children’s blood lead levels were at an all-time high. “You’d have to put your clothes over your face sometimes to breathe,” Belisle said.
A 1974 report from the Federal Public Health Service recommended immediate action to protect human health in the Silver Valley. In 1980, Congress passed the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), which established a federal “Superfund” to help communities clean up hazardous waste sites. There are 1,343 active superfund sites in the nation today.
The Superfund Project Office in Kellogg, Idaho. (Photo by Ilana Newman)
The Bunker Hill Superfund Site, which the EPA added to the NPL in 1983, encompassess a 1,500 square mile area from the Idaho/Montana border in the east, and west to the Coeur d’Alene Lake, a 25-mile long lake and popular recreation spot.
Since Bunker Hill’s inclusion on the NPL, the EPA has partnered with the Idaho Department of Environmental Quality, Panhandle Health District, and the Basin Environmental Improvement Project Commission, among other regional organizations, to clean up contamination. Clean up efforts include removing contaminated soil from residential, commercial, and public properties, containing mine waste at non-operational mines, and maintaining the Bunker Hill Treatment Plant, a water treatment facility that manages contaminated water from historic mine tailings.
Around the time of the area’s inclusion in the NPL, silver production at the Bunker Hill Mine declined rapidly. The Bunker Hill Mine began closing procedures in 1981 due in part to declining silver prices and aging infrastructure. As a result, the small, rural communities of the Silver Valley lost 2,400 jobs in a matter of months.
When Lead Enters the Body
Cass Davis sat at his kitchen table with a box of newspaper clippings at his feet. He remembers drinking water out of mud puddles and streams when he played in the woods as a young child. “The South Fork of the Coeur d’Alene river ran milk white,” Davis said.
Davis grew up in the Silver Valley as the son of a silver miner. He bears the cost of lead contamination in his body. He has learning disabilities and chronic pain, which have hampered his ability to find full-time employment.
“I flunked first grade, and they put me into second grade and then decided, ‘man, he is not ready,’” Davis said. “Not good on a person’s self esteem as a kid.” In school, Davis found it hard to study and pay attention during class. When it came to reading, “these are just words going into my brain without any cohesion,” he said.
Cass Davis’s father was a miner in Idaho’s Silver Valley. (Photo by Ilana Newman)
Despite drinking from questionable sources, Davis said he never contracted Giardia, a common water-borne illness that affects the intestines. He joked that perhaps the parasites that cause Giardia can’t survive in such a lead-poisoned body.
Davis now lives in Moscow, Idaho, a small city near the Washington state border, where he engages in environmental activism with an intergenerational group of activists. It wasn’t until Davis was in his late twenties that he learned his symptoms were likely due to lead poisoning. “My parents knew that pollution was bad, but there was never really an acknowledgement of lead poisoning,” Davis said.
Lead health experts say a common source of lead exposure among children whose parents work in the mines is contaminated work clothes. Children are particularly vulnerable to lead poisoning because toxins enter their blood stream faster than adults, according to Mary Jean Brown, a lead health expert who served as chief of the Lead Poisoning Prevention Branch at the CDC for more than a dozen years. While young children absorb an estimated 50% of ingested lead, healthy adults absorb up to an estimated 10% of the ingested lead, according to Brown.
“What happens with these kids [exposed to lead] when they go to school is they can’t sit still,” Brown said. “That’s a really big deal, especially by the time you get to first or second grade, they may not make the transition from reading to learning, which you should make in about the fourth grade,” Brown said. The symptoms of lead poisoning usually persist throughout a person’s life.
Among adults, the most common source of exposure in the Silver Valley is employment in mines or smelter facilities. As opposed to children, who are more likely to ingest lead, adults who become poisoned are more likely to have inhaled the lead in fine particulate matter. Contamination from inhalation ends up in the bloodstream faster than ingestion, according to Brown.
“Adult lead poisoning looks kind of like early onset dementia,” Brown said. Other symptoms of lead poisoning among adults can include high blood pressure, cardiovascular disease, and reproductive issues, among other things.
Chelation therapy, which can come in the form of injections or pills, is the only medical treatment for lead in the body, but it only works at levels higher than 45 micrograms per deciliter, Brown said. At lower levels, “the chances of the [chelating agent] meeting up with a molecule of lead are pretty small,” Brown said. Chelation therapy is not always prescribed because the treatment can be hard on the body, causing potential side effects like fever, muscle pain, headache, and vomiting, with more severe reactions including kidney damage and heart failure.
Silver Valley native Jeannie Smith stands outside the Silver Valley Community Resource Center office in Kellogg, Idaho. (Photo by Ilana Newman)
“My little sister, she would get in the water, and she would break out from head to toe,” said Jeannie Smith, a member of the Silver Valley Community Resource Center, a local environmental non-profit run by Barbara Miller. “And she has brain tumors now. And I know personally of five people that died of brain tumors here.” A meta-analysis of the link between brain cancer and lead poisoning found that people exposed to lead have an increased risk of developing certain types of brain cancers.
Lead Health Interventions Save Lives
Even after decades of clean up, unsafe lead levels remain a concern among Silver Valley residents and public health officials. But the area’s public health professionals stay vigilant to prevent poisoning.
At Panhandle Health District (PHD), a local health clinic, lead health inspectors keep tabs on blood lead levels, especially among the community’s children. Mary Rehnborg, manager of the Institutional Controls Program at PHD, is in charge of tracking blood lead levels.
Mary Rehnborg is the manager of the Institutional Controls Program at the Panhandle Health District. Rehnborg points to a historic photo of smog over the Silver Valley. (Photo by Ilana Newman)
Rehnborg said miners and their families are usually the ones who suffer the most from elevated blood lead levels. Miners can unknowingly bring home contaminations through their work clothes or shoes, for example.
When Rehnborg’s husband was working at the mine, she told him to leave his clothes outside the house. “You strip down outside, you go shower before you touch anything in the house,” Rehnborg said.
Sometimes, lead poisoning can happen for reasons unrelated to mining.
In June 2023, a Silver Valley child had a blood lead level of more than 30 micrograms per deciliter, more than 30 times higher than the CDC’s current threshold for intervention. After determining that the most likely source of exposure was from living in a home built before the 1978 ban on lead in residential paint and the child’s pica behavior, or consumption of non-food items, a case worker from PHD visited the family’s house and gathered samples from the property. The property samples showed lead contamination, and the case worker helped relocate the child into different housing. The best way to mitigate lead poisoning is to eradicate the exposure source, Rehnborg said.
In an attempt to stay ahead of circumstances like this, PHD hosts an annual lead screening event, offering $50 per child for families to bring their children in for lead testing.
At PHD, health professionals use capillary samples, or finger pricks, to test the blood for lead with machines at their facilities. If blood lead levels come back high, they take a venous sample that gets sent to an FDA-inspected laboratory, according to Rehnborg.
Every year, the Panhandle Health District hosts a screening event encouraging residents to bring their children in for lead testing. (Photo by Ilana Newman)
PHD follows up with children whose blood lead levels exceed the 3.5 micrograms per deciliter threshold set by the CDC to safely eliminate exposure sources.
Even with incentive programs, it can be difficult to get everyone tested. Medicaid requires all children enrolled in the program to be tested for lead at one and two years of age, but a 2016 Reuters report found that millions of children who were required to be tested for lead were not being tested.
“We’re only getting 25 to 30% …That’s kind of what we’re capturing of the childhood population,” Rehnborg said of the children that PHD tests for lead. “I would love if everyone brought their kids in. That would be fantastic, but we can’t force people.”
A Hopeful Decline, and an Uncertain Future
Among those who were tested for lead, the median blood lead level in America dropped roughly 96% in the last four decades, from an estimated 15 micrograms per deciliter between 1976 and 1980, to an estimated 0.6 micrograms per deciliter between 2017 and 2020. Blood lead levels in the Silver Valley also dropped in the last several decades, mirroring nationwide trends. Fifty years ago, the average blood lead level among children tested by PHD dropped from 67 micrograms per deciliter to 2 micrograms per deciliter in 2024. “The work at the Bunker Hill Superfund Site is nowhere near complete but vast improvements have been made and should be celebrated,” the EPA explained in a 2024 report.
Barbara Miller stands outside of East Mission Flats, a mine waste repository managed by the EPA. (Photo by Ilana Newman)
After decades of illness and trauma, many residents still express fear about the effects of lead poisoning on their community, citing concerns about inadequate lead testing data and funding for community health programs. Miller said she has been trying for years to establish a health center specifically dedicated to dealing with lead health issues. But financial support has been hard to come by.
In December of 2025, the Bunker Hill Mining Corporation acquired the Ranger Page Project, claims that include six historic mines previously owned by a Canadian company in a move that further consolidates the Coeur d’Alene Mining District. The Bunker Hill Mining Corporation plans to expand production capacity and modernize metals mining in the region.
The post In Northern Idaho, a Wealth of Silver Begets a Legacy of Lead appeared first on The Daily Yonder.
