Rocky Flats National Wildlife Refuge occupies roughly 5,000 acres of protected shortgrass prairie and shrubland in Jefferson County, nestled between Boulder and Arvada along Colorado's northern Front Range. The refuge sits on the perimeter of the former Rocky Flats nuclear weapons plant, a Cold War-era facility that manufactured plutonium triggers for nuclear warheads from 1952 until 1989. After decades of environmental remediation overseen by the EPA and Department of Energy, the peripheral buffer zone was transferred to the U.S. Fish and Wildlife Service and opened to the public as a national wildlife refuge in 2018. The central cleanup area remains permanently closed and is managed by the Department of Energy.
Trails at Rocky Flats wind through rolling grasslands that provide sweeping views of the Front Range peaks to the west and the Denver metro skyline to the east. The refuge maintains several miles of well-graded hiking and biking trails that are open to non-motorized recreation, including walking, running, and cycling. The terrain is relatively gentle compared to mountain trails, making it accessible to a wide range of fitness levels. Leashed dogs are not permitted on refuge trails, and horseback riding is also prohibited, so the paths stay quiet and well-preserved for foot and bike traffic.
Bird watching is one of the strongest draws to Rocky Flats. The undeveloped grasslands support nesting grassland birds that have lost habitat across much of the Front Range to suburban development, including horned larks, western meadowlarks, and various raptor species. Deer, coyotes, and prairie dogs are also common sightings throughout the refuge. Seasonal wildflower displays bring color to the hills in late spring and early summer.
Visitors should understand that the site's nuclear history remains a source of ongoing public concern and debate. While federal agencies have stated that the perimeter trails are safe for recreational use, some community members and advocacy groups continue to raise questions about residual contamination in soils, particularly during windy conditions when dust can be carried from the central area. Books like 'Full Body Burden' by Kristen Iversen and community organizations have documented the plant's history and ongoing health concerns. Whether you visit Rocky Flats for the trails, the wildlife, or to understand a significant chapter of Cold War and environmental history, approach the refuge with an awareness of its complex past. The refuge is free to visit, with a parking area and trailhead access off Highway 93.