This is a photo of a Sierran Treefrog (Pseudacris sierra). It was one of the taxa sampled in the study: Legacy Mercury Contamination from Historical Gold Mining.
Legacy Mercury Contamination from Historical Gold Mining
September 20, 2024
Legacy Mercury Contamination from Historical Gold Mining
A visualization tool for spatial data on sediment, water, and biota in the Sierra Nevada, California
A visualization tool for spatial data on sediment, water, and biota in the Sierra Nevada, California
Interactive Maps
Interactive Maps
Mercury contamination from historic gold mining poses a risk to human health and the environment. To inform the public and other stakeholders of the history and impact of this situation, the USGS has created a set of interactive maps.
Video Introduction
Video Introduction
This how-to video introduces and demonstrates the features of the interactive maps. This includes the focus of the maps, their symbology, and how to navigate the interface.
Data Release
Data Release
Water, sediment, and biota (animals) were all sampled for this study. The locations were chosen to assess effects from historical mining, with a focus on mercury contamination associated with placer gold mines in the Sierra Nevada.
To understand the contamination caused by historic mining in California, researchers sampled sediment, water, and biota (animals) during the years 1999–2004 and 2011–2012. From the data collected, a set of interactive maps were produced. The maps, along with the data release and introductory video, explain the results of the research.
Related Content
Read about related projects.
Mercury
Mercury is a rare, dense metal, slightly more common than gold in the earth's crust. Mercury occurs in several different forms, the most important of which is methylmercury. Methylmercury is the form most readily incorporated into biological tissues and most toxic to humans. Methylmercury accumulates and biomagnifies in the food chain, reaching highest concentrations in predatory fish such as bass...
Mercury studies at Sulphur Bank Mercury Mine and Clear Lake, California
The abandoned Sulphur Bank Mercury Mine on the shores of Clear Lake in Northern California has been designated as a "Superfund Site" by the U.S. Environmental Protection Agency (EPA). This means that the EPA has determined that the area is contaminated by hazardous waste and requires cleanup because it poses a risk to human health and/or the environment. One of the chief contaminants at the site...
Examining Erosion at Malakoff Diggins State Historic Park, a Sierra Nevada Gold Mine
Located in Nevada County, California, Malakoff Diggins State Historic Park was the Sierra Nevada’s largest hydraulic gold mine, operating from 1866 to 1884. Historically, part of the process of hydraulic mining included using mercury to extract gold from produced sediment through the process of amalgamation. This process left thousands of pounds of mercury and other heavy metals in the area...
Developing Spatial Data on Mineral Deposits Found on Abandoned Mine Lands
Better understanding of mineral deposits and their impact on the environment, including the water system, is necessary for the protection of public health. The USGS is working with other federal and state agencies to identify the environmental behavior of these deposits and their waste products. USGS scientists are using geospatial data (data that can be mapped) to prioritize abandoned mine land...
Mercury Methylation and Bioaccumulation in the Bear River Watershed
Extensive mercury use during historical gold processing has resulted in widespread mercury contamination and bioaccumulation of methylmercury in watersheds in the northwestern Sierra Nevada (Slotton and others 1997; Alpers and Hunerlach, 2000). A recent USGS report (May and others, 2000) documented the presence of elevated mercury in fish tissues in five reservoirs in the Bear River, Deer Creek...
Lower American River Mercury
Dredging operations for gold along the American River began in the 1860s and continued through the early part of the 20th century, ending about 1962. More than one billion cubic yards of gravel were dredged, making the American River dredge field the second largest in California.
Pseudacris sierra - Sierran Treefrog
This is a photo of a Sierran Treefrog (Pseudacris sierra). It was one of the taxa sampled in the study: Legacy Mercury Contamination from Historical Gold Mining.
Malakoff Diggins State Historic Park
Malakoff Diggins State Historic Park
Malakoff Diggins State Historic Park
Gold Pan with Mercury
Gold pan with more than 30 grams of mercury from 1 kilogram of mercury-contaminated sediments collected in a drainage tunnel.
Gold pan with more than 30 grams of mercury from 1 kilogram of mercury-contaminated sediments collected in a drainage tunnel.
Related Content
Read about related projects.
Mercury
Mercury is a rare, dense metal, slightly more common than gold in the earth's crust. Mercury occurs in several different forms, the most important of which is methylmercury. Methylmercury is the form most readily incorporated into biological tissues and most toxic to humans. Methylmercury accumulates and biomagnifies in the food chain, reaching highest concentrations in predatory fish such as bass...
Mercury studies at Sulphur Bank Mercury Mine and Clear Lake, California
The abandoned Sulphur Bank Mercury Mine on the shores of Clear Lake in Northern California has been designated as a "Superfund Site" by the U.S. Environmental Protection Agency (EPA). This means that the EPA has determined that the area is contaminated by hazardous waste and requires cleanup because it poses a risk to human health and/or the environment. One of the chief contaminants at the site...
Examining Erosion at Malakoff Diggins State Historic Park, a Sierra Nevada Gold Mine
Located in Nevada County, California, Malakoff Diggins State Historic Park was the Sierra Nevada’s largest hydraulic gold mine, operating from 1866 to 1884. Historically, part of the process of hydraulic mining included using mercury to extract gold from produced sediment through the process of amalgamation. This process left thousands of pounds of mercury and other heavy metals in the area...
Developing Spatial Data on Mineral Deposits Found on Abandoned Mine Lands
Better understanding of mineral deposits and their impact on the environment, including the water system, is necessary for the protection of public health. The USGS is working with other federal and state agencies to identify the environmental behavior of these deposits and their waste products. USGS scientists are using geospatial data (data that can be mapped) to prioritize abandoned mine land...
Mercury Methylation and Bioaccumulation in the Bear River Watershed
Extensive mercury use during historical gold processing has resulted in widespread mercury contamination and bioaccumulation of methylmercury in watersheds in the northwestern Sierra Nevada (Slotton and others 1997; Alpers and Hunerlach, 2000). A recent USGS report (May and others, 2000) documented the presence of elevated mercury in fish tissues in five reservoirs in the Bear River, Deer Creek...
Lower American River Mercury
Dredging operations for gold along the American River began in the 1860s and continued through the early part of the 20th century, ending about 1962. More than one billion cubic yards of gravel were dredged, making the American River dredge field the second largest in California.
Pseudacris sierra - Sierran Treefrog
This is a photo of a Sierran Treefrog (Pseudacris sierra). It was one of the taxa sampled in the study: Legacy Mercury Contamination from Historical Gold Mining.
This is a photo of a Sierran Treefrog (Pseudacris sierra). It was one of the taxa sampled in the study: Legacy Mercury Contamination from Historical Gold Mining.
Malakoff Diggins State Historic Park
Malakoff Diggins State Historic Park
Malakoff Diggins State Historic Park
Gold Pan with Mercury
Gold pan with more than 30 grams of mercury from 1 kilogram of mercury-contaminated sediments collected in a drainage tunnel.
Gold pan with more than 30 grams of mercury from 1 kilogram of mercury-contaminated sediments collected in a drainage tunnel.