Month: March 2026
THE DIRT: Prichard Creek Restoration
Written by guest author: Cathy Gidley, North Idaho Program Manager for Trout Unlimited
In 1879, AJ Prichard discovered gold in Prichard Creek, setting off the mining rush in the Coeur d’Alene basin. Prichard Creek is a tributary to the North Fork Coeur d’Alene River and was the site of several hard rock mines and mill sites in the 1900s. Placer and lode mining dominated the early mining efforts until a large dredge was brought in from Alaska by the Yukon Gold Company in 1917, operating until 1926. The massive dredge was 106 feet long, 44 feet wide, and 6 stories tall. It worked 24 hours a day, manned by a crew of 12. Reports indicate that it dug down in excess of 20 feet into the river bed. The dredge turned over about five miles of the creek and floodplain, leaving behind a barren landscape of tailings. The disturbance altered the stream channel, causing water to flow subsurface and impairing the habitat and river function throughout the entire length of Prichard Creek to the confluence. Today, an approximately 3 mile section of the creek near the town of Murray loses water for a portion of every year. Westslope cutthroat trout and other native fish species persist in Prichard Creek, but lack the connection to the headwaters upstream.
The Idaho Forest Group, who owns 10.5 miles adjacent to the stream channel, became interested in restoring the degraded stream and entered into a partnership with Trout Unlimited, with funding and support from the Restoration Partnership, sponsored by Idaho Department Environmental Quality. Though the partnership between a timber company and conservation group was unusual, it has proved to be extremely successful. After years of planning, work was completed in 2023 to improve habitat and river function in the lower 4 miles of the creek. A total of 62 log structures with various objectives were constructed, and over 5,000 willow stakes and 3,000 riparian and upland plants were planted. After 2 years the structures are showing success in creating pools, dividing flow to move water into side channels, trapping sediments, and creating islands of vegetation. The new structures have attracted the attention of beavers and they have moved back into the main channel in some areas, having been largely absent- the valley bottom was likely historically inundated and teeming with life. The IFG property was placed into a conservation easement with the Kaniksu Land Trust, ensuring that the improvements are sustained into the future.
Building on the success of the initial project, a design process is currently underway to work on the next phase which will address the dredged area and dewatered section of the creek downstream of Murray. It will likely be several years before the project is implemented. Project partners will host meetings to keep the public informed regarding the next phase. AJ Prichard is buried in the cemetery near Murray, his legacy evident throughout the valley. Through partnerships, our hope is to honor that legacy and restore the rich environment that attracted Prichard and countless others to this region.
For additional information on projects: northidahotu.org Cathy Gidley, North Idaho Program Manager cathy.gidley@tu.org
The Dirt is a series of informative articles focused on all aspects of cleanup efforts associated with the Bunker Hill Superfund Site. Our goal is to promote community awareness of contamination issues, to provide tools for protecting public health, and to keep the community informed of current and future cleanup projects. The Dirt is a group of committed and local experts from multiple agencies including the Basin Environmental Improvement Project Commission, Panhandle Health District, Shoshone County, Silver Valley Economic Development Corporation, and the Idaho Department of Environmental Quality.
THE DIRT: How Flooding in the Bunker Hill Superfund Site is Different
While flooding in North Idaho is not uncommon, high flow events like the one that occurred in December 2025 can have consequences that extend beyond immediate water damage. When high flows sweep through the Coeur d’Alene River Basin, they interact with a landscape shaped by more than a century of mining activity. Historic discharges mean that floodwaters have the potential to move metals and other pollutants downstream, affecting both the environment and the communities that live along these waterways.
Flood damage usually brings to mind washed-out roads, detours, and debris—but when floods hit contaminated waterways like those in the Coeur d’Alene River Basin, the risks go far beyond the obvious. From 1884 until 1968, Silver Valley mines directly discharged millions of tons of metals contaminated mine waste into the South Fork of the Coeur d’Alene River and its tributaries. These wastes traveled downstream into the main channel of the Coeur d’Alene River and chain lakes of the Lower Basin, leaving a devastated landscape behind. The waters of the South Fork and main stem of the Coeur d’Alene River ran milky gray, the vegetation lining the banks died off, and wildlife abandoned the area. The magnitude and duration of historic practices left a vast legacy of contaminated sediment throughout the river corridor and its connected aquatic and floodplain habitats.
The increased volume and speed of water traveling downstream during flood events can greatly disturb these historic sediments, dislodging them from the riverbed and banks, carrying them downstream and into the nearby low-lying lands. As weather conditions improve, floodwaters begin to recede, and the process of deposition begins. Deposition is a normal process that occurs as floodwaters lose their velocity and begin to subside. The sediments begin to settle out and remain on the surface of the land after the waters return to normal levels in the river. When this occurs within contaminated areas, contaminated sediments can be left behind.
As the years passed with no direct discharges of mine waste to the river and remediation began throughout the Coeur d’Alene River Basin, the land showed signs of recovery. The waters of the Coeur d’Alene River no longer ran milky gray with mine waste, the floodplain became revegetated, and wildlife began returning to the area. River and lake front properties in the Lower Basin no longer looked polluted and people began to view the land as prime recreational real estate. Unfortunately, these properties are still contaminated, and continue to pose a risk to human health, wildlife, and the environment.
When properties along the river and portions of the chain lakes are developed for recreational or residential use, owners are required under Panhandle Health District’s Institutional Controls Program to install clean barriers anywhere contaminated land is being developed, actively used, and/or maintained. Clean surfaces such as gravel, topsoil, asphalt, or concrete, when installed properly, help protect those using the land from exposure to metals such as lead, arsenic, and cadmium, and these clean barriers have been proven to reduce exposure to these metals. However, when floodwaters inundate remediated areas, barriers can be compromised in several ways: gravel may erode or become mixed with contaminated sediments, concrete or asphalt can crack or heave, and vegetated or “greened” areas can be buried under a thin layer of contaminated silt that is not always visible at the surface. Over time, these conditions can reduce the effectiveness of the barrier. It is the property owner’s responsibility to protect and maintain their barriers, which can be a costly expense.
Flooding can undo years of remediation, leaving contaminated sediments on properties and compromising protective barriers. Property owners along the Coeur d’Alene River and chain lakes should inspect and maintain clean surfaces after every flood and contact the Panhandle Health District (PHD) for guidance to keep their land safe from lead, arsenic, and cadmium exposure.
The Dirt is a series of informative articles focused on all aspects of cleanup efforts associated with the Bunker Hill Superfund Site. Our goal is to promote community awareness of contamination issues, to provide tools for protecting public health, and to keep the community informed of current and future cleanup projects. The Dirt is a group of committed and local experts from multiple agencies including the Basin Environmental Improvement Project Commission, Panhandle Health District, Shoshone County, Silver Valley Economic Development Corporation, and the Idaho Department of Environmental Quality.
