Army Rocky Mountain Arsenal


RMA Beginnings

Known today as an urban national wildlife refuge, the Rocky Mountain Arsenal traces its beginnings to the Dec. 7, 1941, attack on Pearl Harbor, which brought the United States into World War II. The U.S. Army constructed the Arsenal in 1942 to develop chemical weapons as a deterrent against the Axis Powers. The U.S. Army selected 17,000 acres of farm land just 10 miles northeast of Denver in Commerce City, Colorado, as the site of the new Arsenal.

As production declined at war’s end, the U.S. Army leased some of the facilities to private companies, one of which Shell Oil Co. purchased, for the production of agricultural chemicals. The U.S. Army later reactivated Arsenal facilities for Cold-War weapons production and demilitarization. The Arsenal also played a role in America’s space exploration by manufacturing the rocket fuel used to power the Apollo 11 flights.



Manufacturing and Environmental Cleanup

Although the U.S. Army and Shell used accepted disposal practices of the time, decades of chemical and agricultural production led to contamination of some of the soil, structures and groundwater. Contaminants included solvents, metals, pesticides, and miscellaneous manufacturing-related chemicals.

In 1982, all production at the site stopped, and the Arsenal’s mission changed to environmental cleanup and restoration. The site was placed in 1987 on the EPA’s National Priorities List, which is also known as the Superfund list.



Discovery of Roosting Bald Eagles

While the framework for the comprehensive environmental cleanup was being developed, work crews discovered a pair of roosting bald eagles at the site, which prompted the U.S. Fish and Wildlife Service to establish a field office at the RMA to help manage the abundant wildlife. Soon after, Congress enacted legislation designating the RMA as a future national  wildlife refuge.

The U.S. Army and Shell conducted the $2.1 billion environmental cleanup of the site in collaboration with the Environmental Protection Agency, Colorado Department of Public Health and Environment and Tri-County Health Department. All surface work related to the environmental cleanup ended in 2010, one year ahead of schedule and within budget. Groundwater treatment will continue until all water leaving the site meets state and federal standards.



Refuge Creation

As cleanup actions were successfully completed, the U.S. Army transferred land to the U.S. Fish and Wildlife Service to create and later expand the Rocky Mountain Arsenal National Wildlife Refuge. Today, the Refuge encompasses more than 15,000 acres of restored shortgrass prairie and provides habitat to more 300 species of wildlife, including American bison, bald eagles, mule and white-tailed deer, burrowing owls and black-footed ferrets.


Long-Term Operation and Maintenance

The U.S. Army will permanently retain and manage about 1,000 acres of Arsenal land that contain the landfills, waste consolidation areas and groundwater treatment facilities to ensure they remain protective of human health and the environment.

Rocky Mountain Arsenal

6550 Gateway Road

Commerce City, CO 80022-1748

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