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Sarah Kanouse, Cotter Uranium Mill, Canon City, Colorado, 2010, Flickr


Cotter Uranium Mill

Located south of Cañon City in Fremont County, Colorado, the Cotter Uranium Mill opened in 1958 and was used as a uranium processing site for nuclear weapons and fuel. Cotter Corporation produced yellowcake as well as vanadium and molybdenum as byproducts. Yellowcake is the solid form of mixed uranium oxide, which is made from uranium ore in the milling process. The mill was originally licensed by the Atomic Energy Commission, but the authority for the licensing was transferred to the Colorado Department of Public Health and Environment in 1968 when Colorado became an The Nuclear Regulatory Commission's Agreement State Program transfers federal regulatory authority over nuclear materials to state governments who have met certain standards for training, inspection, and oversight activities.Agreement State.

Historical mill operations and disposal practices released radioactive and metal contamination into the environment. Waste was stored in unlined ponds until 1978, and in 1984 the 2,600-acre uranium mill and areas of mill-associated contamination, including the Lincoln Park community, were added to the National Priorities List (“Superfund”). Despite this designation, uranium ore was processed on site until 2006, and the state allowed Cotter to maintain operations until 2011. It has since been divided into two “operable units" for remediation: the contaminated mill site (including its ponds) and the Lincoln Park neighborhood. Since reclamation efforts began, Cotter Corporation had been cited for numerous environmental violations. According to a 2014 Agency for Toxic Substances and Disease Registry report, contaminated water remains a risk for local residents of Cañon City and those living downstream along the Arkansas River. In March 2018 the Superfund site was bought by Colorado Legacy Land along with the Central City Schwartzwalder Mine. The two projects encompass a total of 3,300 acres of freehold land which are subject to a mine reclamation permit and radiation materials licenses.


Alexco Resource Corp. "Alexco Environmental Group and Colorado Legacy Land LLC Partner to Cleanup Legacy Uranium Mining and Processing Sites in Central Colorado." CISION PR Newswire. April 10, 2018. Accessed July 31, 2020.

Earthworks. "Lincoln Park / Cotter Mill." Accessed July 31, 2020.

Finely, Bruce. "Cotter Negotiates amid Spills and Uranium Spike by River in Cañon City." The Denver Post, March 13, 2014. Accessed July 31, 2020.

Rose, Sarah. "Lincoln Park Superfund Site Under New Ownership." Cañon City Daily Record, April 15, 2019 [last updated]. Accessed July 31, 2020.

U.S. Environmental Protection Agency. "Lincoln Park Cañon City, CO Cleanup Activities." Accessed July 31, 2020.
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