The Rocky Mountain Arsenal is a national wildlife refuge with a cleanup history

On the edge of Commerce City, one of the larger urban wildlife refuges in the country spreads across old prairie, with bison, deer, raptors, and prairie dogs. The Rocky Mountain Arsenal National Wildlife Refuge is free to visit, with hiking trails and a wildlife drive.

Its history is part of the story, not a secret. The land was once used by the Army to make chemical weapons and later by industry to make pesticides. That left serious contamination, and the site went through a long, major federal cleanup before becoming the public refuge it is today. Federal and state agencies have tracked the cleanup and long-term monitoring on the property.

For a visitor, the practical takeaways are simple. The refuge is managed by the U.S. Fish & Wildlife Service, so its hours, trail rules, and any seasonal closures come from that agency. Some areas stay off-limits, both to protect wildlife and as part of how the cleaned-up land is managed. Following the posted rules is the right call.

This is a place where Colorado history, industry, and wildlife all sit on the same ground.

For current visiting information and the cleanup background, start with the U.S. Fish & Wildlife Service refuge page and the state health department.