Elkhorn Mining District Site

History

In 1870 the Hard Rock Mining District was established. The Elkhorn Mine was the main producer in the district. The mine primarily produced silver and gold ore. This fueled community growth decade later. Continuous mining ended in 1912.

EPA conducted a preliminary assessment from 2017 to 2018. In 2019 and 2020 EPA sampled several areas under a site inspection.

Current Activities

EPA is interested in getting a better understanding of contamination in the area surrounding the Elkhorn Mining District and filling in some data gaps. EPA is contacting owners in the area to request consent for access to sample properties. EPA will not sample on a property without a consent for access form.

EPA is currently conducting an expanded site inspection in the area. This summer, EPA plans to collect samples for:

• Soil
• Surface water
• Groundwater

If you are interested in signing up for sampling, you can sign the consent for access form(pdf)(211KB). You can return the form via email to EPA’s Ryan Monahan at monahan.ryan@epa.gov or mail it to:

Ryan Monahan, EPA SEM-EMB-ARS
1595 Wynkoop St, Denver, CO 80202

Site Documents & Maps

• Sampling Consent for Access Form(pdf) (211KB) 
• Site Map (wide view) (pdf) (1.4MB)
• Site Map, Zoom (pdf) (1.3MB)

What Are the Risks at the Site?

EPA is investigating whether metals concentrations at the site pose an unacceptable risk to humans or wildlife. Prior sampling in the Elkhorn area has shown elevated levels of metals. These include: arsenic, lead, cadmium and zinc. Elkhorn Creek is listed as an impaired stream based on metals not supporting the aquatic life standard.

Several mine tailings piles are located near the Elkhorn area and have elevated metals levels. EPA has observed recreational use on some of the tailings piles in the area, particularly the sandy tailings piles. EPA recommends users avoid recreating on mine tailings piles.

Until More Information is Available, Protect Yourself from Mine Waste: 

Keep Clean, Eat Clean, Play Clean

Waste rock dumps, tailings, adit discharges, streams, and groundwater in the area pose a potential risk to users.  To minimize exposure:

• Bring water for drinking, cooking, and washing. Do not use water from the stream - even if it is filtered!
• Remove dirt from clothes, toys, pets, and equipment before leaving the area and wear masks when riding on off-road trails.
• Eat on a table or blanket in grassy areas.
• Do not harvest edible plants from floodplain areas.
• Reference DEQ state guidelines for safe fish consumption(pdf) 

Contact the EPA, the U.S. Forest Service, or the Montana Department of Environmental Quality if you have questions on the risks or best practices.