For most of the Cold War, the grassland west of Broomfield, Colorado, was where the United States machined plutonium triggers for its nuclear arsenal. This fall, it is where 50 elk hunters have been sitting in portable blinds along the Front Range, waiting for a bull to step out of the tall grass. Rocky Flats National Wildlife Refuge, which wraps around the footprint of the old Rocky Flats Plant, is hosting its first big-game season, a limited pilot elk hunt run by the U.S. Fish and Wildlife Service with tags drawn through Colorado Parks and Wildlife.
The hunt is small, tightly regulated and, given the ground it covers, inevitably controversial. It also carries an unusual footnote. According to 9News, the agency's draft hunt plan, dated January 2026, recommends that hunters not eat elk liver because of chemical findings in testing. That advice sits alongside federal assurances that the meat itself is safe and that the refuge meets environmental standards, and it gives anyone thinking about applying for a future tag something specific to weigh.
Too Many Elk on Too Little Prairie
The Fish and Wildlife Service is not framing this as a recreation giveaway. Its argument is about numbers. Elk on the refuge have more than doubled since 2019, according to reporting by KUNC and the Mountain West News Bureau, and the herd now sits at roughly 700 animals. The agency wants it brought down to somewhere between 200 and 250.
At 5,237 acres of wetlands, uplands and riparian habitat, Rocky Flats is not a large property by Western standards. A herd that size, concentrated on a fenced patch of tallgrass prairie hemmed in by suburbs and highways, eats down the vegetation the refuge was set aside to protect. The agency says the current population exceeds what the landscape can support, threatens rare plants and raises the risk of disease moving through animals that are packed together. Elk on the Front Range have few natural predators left to thin them, and the surrounding communities are not going to welcome wolves or mountain lions as a management tool. That leaves hunters.
The pilot also fits a broader federal push. The hunt is part of the Interior Department's expansion of hunting and fishing opportunities on public lands, a priority of the Trump administration, and Rocky Flats was one of the more symbolically loaded places to add to the list.
From Plutonium Triggers to Prairie Refuge
Rocky Flats produced the plutonium cores, or "triggers," that sat at the heart of American nuclear weapons for decades. The plant closed in 1989. A cleanup that cost about $7 billion was declared complete in 2005, the same year the refuge was established on paper, and the land opened to the public as a wildlife refuge in 2018. The inner core where the plant buildings stood is still closed and remains under the U.S. Department of Energy, not the refuge.
That history has never fully settled. Federal and state agencies point to air and soil monitoring showing contamination within standards; in a 2020 assessment, most soil samples came back below background levels. A sign at the refuge entrance makes the case in plain terms: "If you visited the refuge hundreds of times in a year, your dose still would be much less than a medical X-ray."
Not everyone is persuaded. Chris Allred of the Rocky Mountain Peace and Justice Center, a group that has pushed to close the refuge, pointed to a 2024 sampling effort by non-government scientists that detected plutonium in air filters collected during high winds. "We believe there is abundant evidence for why that site still poses a risk to human health," Allred said.
David Havlick, a professor at the University of Colorado Colorado Springs, raised a different concern: that turning the place into a hunting ground risks smoothing over what it was. "I think it's important we don't lose sight of what happened there and why it is the kind of place that it is," he said.
What the Testing Says About the Meat, and the Liver
For a hunter, the practical question is simple: can the animal go in the freezer? On that point, the federal answer is yes. The agency says there are no restrictions on eating elk taken from the refuge.
The hunt plan leans on older work as well as new sampling. A 2005 study found some radioactive contaminants in deer tissue, and the plan cites it while estimating minimal risk from eating deer meat. The plan's summary puts it this way: "The results indicate no significant uptake of contaminants by deer or other wildlife species at the site."
Refuge manager David Lucas said the agency anticipated the question. "Obviously, we have thought about that," he said. "The animals that we collected in 2023 were sampled for radionuclides, and all were 'non-detect' in all tissues."
The liver caveat
The liver recommendation is where the picture gets more nuanced. As 9News reported, the draft hunt plan advises hunters against eating elk liver because of chemical findings in testing, a distinction from the radionuclide results Lucas described. The recommendation is not a ban, and it does not extend to the muscle meat that makes up nearly everything a hunter brings home.
Separately, a preliminary scientific analysis of PFAS exposure in elk around the former Rocky Flats site has looked at liver and muscle tissue, reporting PFOS, one of the so-called "forever chemicals," in liver samples, including from control animals taken elsewhere, while not detecting it in muscle. Its authors cautioned that the sample was small. Whether that work is the basis for the plan's advice is not spelled out in the reporting, but the pattern is familiar to hunters in other states. The liver filters the blood and tends to concentrate persistent chemicals, which is why wildlife agencies in Wisconsin and New Hampshire, for example, have issued liver-specific advisories for deer in contaminated areas while leaving the backstraps and roasts alone.
For most elk hunters, giving up the liver is not much of a sacrifice. Plenty of people leave it in the field anyway. Those who prize it fried with onions the morning after a kill will want to read the final hunt plan closely before the next season.
How the Rocky Flats Hunt Works
The pilot runs on two seasons, both closed on Tuesdays and Wednesdays, which the refuge calls rest days. Archery ran September 17 through September 28. The firearm season opened October 1 and continues through December 14, and archery equipment is also allowed in that window.
Access was limited. Colorado Parks and Wildlife issued 50 tags by lottery, and every hunter had to attend a mandatory orientation. All 2026 tags have been distributed. The refuge's regulations require each hunter to carry a Colorado elk license valid for Rocky Flats along with the signed refuge brochure.
Rules that set this hunt apart
The regulations reflect a small refuge crowded by neighbors, trail users and a federal cleanup site. Among the requirements in the Fish and Wildlife Service's hunt regulations:
Center-fire rifles and handguns are prohibited, as is the use or possession of lead ammunition while hunting. Dogs are not allowed. Hunters may reach the hunt area only from designated parking areas or trails, and may ride horses, bicycles or Class 1 e-bikes on established trails, but off-trail hunting has to be done on foot. ATVs, UTVs and other off-road vehicles are banned.
Portable blinds are permitted, as are blinds built from dead and downed vegetation. Hunter orange is required during the firearm season, both while hunting and during retrieval, and it applies to everyone in the party. A hunter may bring one non-hunting mentor or assistant into the field, and four or five additional people can help pack out a downed animal on foot, horseback, bicycle or game cart.
The most Rocky Flats-specific rule concerns the fence line. Access to Department of Energy land is prohibited. If a wounded elk crosses onto it, the hunter must contact the refuge for help rather than follow. Everything, from trash to spent casings and shells, has to leave with the hunter at the end of each day, and the refuge manager can close all or part of the hunt area for safety or management reasons. Hunters are also reminded that staff, researchers, contractors and other visitors may be in the area, and that shooting toward roads, houses, vehicles, livestock or infrastructure is off limits.
A Pattern Across Former Weapons Sites
Rocky Flats is not the first Cold War property to become a refuge, or to let hunters in. Rocky Mountain Arsenal National Wildlife Refuge, a former chemical weapons and pesticide manufacturing site northeast of Denver, is part of the same Colorado Front Range refuge complex and is better known for its bison herd than its past. Across the country, former military and Energy Department lands have become some of the most intact habitat in their regions precisely because they were fenced off from development for decades.
That irony is part of what makes Rocky Flats compelling, and part of what makes critics wary. The same isolation that let elk and native prairie thrive also kept the public away from a site that handled some of the most hazardous material ever produced. Opening it to hunting asks people to trust the cleanup in a more personal way than a walk on a trail does. A hiker passes through. A hunter takes a piece of the place home and feeds it to his family.
What Comes Next for Front Range Hunters
The 2026 season is a pilot, and how it performs will shape what follows. For 2027, the refuge points hunters to Colorado Parks and Wildlife's big-game brochure for lottery details. If the agency's target of 200 to 250 elk holds, there is a long way to go from a herd of about 700, and 50 tags in a single season will not get there on their own. Expect the program, if it continues, to be adjusted based on harvest results and whatever the final hunt plan says about consumption.
For the hunter weighing an application, the calculus is fairly clear. The tag is hard to draw, the rules are strict, the weapons options are narrower than on most Colorado units, and the backdrop includes one of the most debated cleanup sites in the country. In return, it offers a rare chance to hunt elk on open prairie within sight of the Denver metro area, on ground where federal testing has found the meat clean. Read the regulations, plan to leave the liver, and keep the Energy Department fence in mind when it is time to take the shot.
Questions about the hunt go to the refuge at rockyflats@fws.gov or 303-289-0232.
