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Sarah Kanouse, Las Colonias Park, built on the remediated site of the Climax Uranium Mill in Grand Junction, Colorado, 26 May 2014, Flickr


Climax Uranium Mill

From 1950 to 1970, Climax Uranium operated a mill along the north bank of the Colorado River in Grand Junction. The facility began in 1899 as a sugar beet mill. In 1950, the Climax Uranium Company reconfigured the site to function as a vanadium and uranium mill. Occupying 114 acres, the processing site produced 2.2 million tons of milled ore until 1970. An estimated 300,000 tons of radioactive mill tailings were sold and transported to more than 4,000 properties to be used in concrete and mortar; houses, schools, commercial buildings, sidewalks, an airfield, and a shopping mall were constructed with radioactive tailings used as aggregate or fill. 

Remediation of the actual site began in the mid-1980s, as part of the federal Uranium Mill Tailings Remedial Action Project. Climax Uranium Company demolished 8 of the 12 main mill buildings at the processing site, decontaminated equipment to be sold, and buried what couldn’t be decontaminated inside the tailings pile. Construction of a more stable disposal site began in 1990, and 4.4 million cubic yards of contaminated processing site materials and radioactive waste were transported to the cell for storage and burial. 

Following surface remediation, the plot was transferred to the City of Grand Junction through a quitclaim deed in 1997. The Department of Energy declared cleanup complete in 1998, and the former mill site has now been redeveloped into a waterfront park called Las Colonias, named after the Latino community historically displaced by the mill. Las Colonias Park contains a playground for children, covered picnic area, restrooms, walking trails, and a concrete-paved riverfront trail built on a flood-control dike.


Carr, Jonathan and Claire Kempa. "The History of Las Colonias Park: Historic Crossroads Along the Riverfront of Grand Junction, Colorado." Prepared for the City of Grand Junction Parks and Recreation Department. April 2015. Accessed June 22, 2021.

Center for Land Use Interpretation. "Grand Junction Climax Uranium Mill Site, Colorado." clui.org. Accessed July 31, 2020.

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