Warning to Americans enjoying the great outdoors: Beware of feathers.

Visitors to the 3,000-acre National Wildlife Refuge in Mason Neck, Va., for example, could be arrested for possession of common bird feathers under a law enacted nearly a century ago. The refuge's woods and wetlands are home to roughly 14 bald eagle nests during peak season in winter. That's nearly 50 bald eagles molting feathers onto the forest floor, feathers that are illegal even to pick up off the ground.

Bald eagles are not the only bird whose feathers are protected. From Florida to Alaska, more than 100 other species of birds are covered by federal statutes.

"There are probably some people who have them and don't know it's illegal," said Stacy Allen, a National Park Service staffer at the refuge.

Feather regulation has become so complex that the federal government must pay for a repository of bird parts in Colorado simply to try and reconcile feather laws with religious rights. And none of these laws address the primary threat to bird populations today: the widespread use of turbines for power generation.

The hiker, the birder, the school kid who thinks a loose feather on a forest floor might make good show and tell, all stand in danger of losing their liberty. Thanks to the Migratory Bird Treaty Act, enacted 98 years ago, and the Bald and Golden Eagle Protection Act of 1940, possession of feathers of any migratory bird other than the pigeon, starling or house sparrow makes one an outlaw.

The laws remain on the books even though the bald eagle was taken off the endangered species list in August 2007. These laws have made criminals of unsuspecting nature lovers and Native Americans who consider plumage sacred.

In 2006, federal agents raided a powwow and seized feathers being used by the Lipan Apache, a tribe recognized by the state of Texas, but not the federal government which — paradoxically — still considers its members Native Americans. The tribe's pastor, Robert Soto, considers eagles "a great gift from God, our creator," and fought the government for a decade. With pro-bono assistance from the Becket Fund for Religious Liberty, Soto battled the federal government for a decade before finally prevailing in June.

"It's a prime example of bureaucratic blinkers," said Luke Goodrich, deputy general counsel for the Becket Fund. "I don't think the federal government has an ax to grind. It just has to have a myopic focus on one policy goal and gives extremely little weight to the religious practices of these Native Americans. It is a feature common to many religious liberty cases today – they don't think about the value of religious practices and freedom."

"It would seem the federal government should have some basic common sense," said R.J. Smith, a past president of the Monmouth, N.J., Nature Society and now a fellow in Washington at the Competitive Enterprise Institute's Center of Energy and the Environment.

The notion the state should "own" wildlife is found as far back as William the Conqueror who, after the Norman Conquest of England in the 11th century, decided that wild animals belonged to the king and the king alone. Around the time Fletcher Christian was sailing the South Pacific with his mutinous crew, his brother, Edward, a Cambridge law scholar, posited that wildlife, with its inherently fluid movement, belongs to individual landowners.

Edward Christian challenged legal thinking sided with the monarch or the state. "American social conditions were different because of the enormous amount of land that was undeveloped," said Thomas Lund, a University of Utah Law School professor whose seminal work, "American Wildlife Law," was published in 1980. It was not until the U.S. Supreme Court majority upheld the Migratory Bird Treaty Act that the matter was settled in the feds' favor, Lund said.

But times have changed. The federal government today spends millions in treasure and sweat running covert operations with code names that sound like they came from an old "F Troop" script: Operation Pow Wow, Operation Silent Wilderness and Operation Game Thief. These nationwide campaigns have resulted in hefty fines and prison sentences. In addition, the government's monopoly on the trade or possession of eagle feathers means it spends another $350,000 each year running the National Eagle Repository in the Rocky Mountain Arsenal National Wildlife Refuge northeast of Denver.

In a freezer warehouse on a Colorado plain, a team of three full-time employees and two volunteers wear masks and modified hazmat suits and spend their days collecting, cataloging and plucking at the carcasses of eagles which, when not being handled, hang suspended in plastic bags. They come there from all over the country, and, given the rate at which wind turbine farms are killing birds, in greater numbers than they used to.

The Eagle Repository is funded strictly through fines and penalties assessed through the federal investigations, and while privatizing the operation is an idea floated from time to time it has never been fully explored, said Steve Olberholtzer, special agent in charge of law enforcement for the U.S. Fish and Wildlife Service's mountain-prairie region encompassing Colorado, Kansas, Montana, Nebraska, North Dakota, South Dakota, Utah and Wyoming.

"A lot of the work involves dealing with eagles in various stages of decomposition," he said. "It's not the most glamorous work."

The undercover operations are hardly something out of a spy thriller. Instead, they largely involve plainclothes agents purporting to be interested in acquiring eagle carcasses or parts.

Just how much taxpayers spend on feather protection and how many hours agents spend on these eagle investigations isn't clear, and the Fish and Wildlife Service declined to say. Overlapping agencies also make tracking the money harder. Overall, the Fish and Wildlife Service budgeted almost $75 million for its law enforcement efforts in the current fiscal year. The president's budget proposal for 2017 seeks a modest increase. Two years ago, about 10 percent of the budget funded migratory bird enforcement operations, according to representatives of the House Natural Resources Committee.

The Fish and Wildlife Service does not disclose how many investigations it conducts into the illicit eagle trade, or how many arrests such operations yield. Annual reports say it investigated 638 cases related to the Migratory Bird Treaty in 2014 and 911 in 2013, although how many of those involved bald or golden eagles is anyone's guess. A 2010 meeting of the "Eagle Feather Working Group" drew people from seven Native American tribes and various federal officials. At that meeting, the "USFWS stated that in the last round of enforcement activity USFWS has conducted 195 criminal investigations into the illegal possession of eagle feathers and/or parts," according to meeting notes.

The chief targets of these investigations are members of Native American tribes, the only Americans allowed to possess eagle feathers and carcasses. Native tribes are permitted exceptions for the purpose of religious ceremonies, but some experts believe these laws have created a black market in birds that wouldn't otherwise exist. It certainly creates a huge backlog, even for incarcerated Native Americans who have their own separate online request forms. It can take years for an application for a prized immature golden eagle carcass to be filled.

"I think what we're on the edge of here is making these things a commodity," said Jim Tate, a former science advisor to the interior secretary and now a regent with the Potomac Institute for Policy Studies. "How do you value a noncommodity resource like an attractive bird feather? I think this is typical of so many of our laws where we are trying to solve a problem with a hammer instead of a scalpel."

Experts divide on how much of a problem America faces with birds that are no longer listed on the Endangered Species Act.

"We have lost lambs from our corral. We feel certain that they are taken by eagles," a California rancher told the scientific magazine the Condor in 1936. "We do not know what eagles killed them, so we kill all the eagles we can."

Eagles were once killed by ranchers and farmers who considered the feathered hunters a threat to livestock, but since that time, sustained education efforts have taught that eagles aren't a genuine threat.

The national bird's population also shrank when pesticides including DDT were widely used, but the eagle population has made a strong recovery. There were nearly 9,800 nesting pairs in 2006, according to the Fish and Wildlife Service, up from just 487 in 1963.

The sacred status of these birds in many Native American cultures means recognized tribes are unlikely to pose a significant threat to the eagle population, according to Rob Ramey II, a field biologist and president of Wildlife Science International in Nederland, Colo.

"People think if the laws were changed we'd see a huge increase in the take of eagles," Ramey said. "I think culturally we're past that. The presumption that human depredations are a grave threat to eagles is bogus."

The push for renewable energy now poses the biggest threat, according to Ramey and others. Modern windmills dotting landscapes across the American West kill at least 100 of the majestic birds every year in California alone, according to conservative estimates. In all, about 573,000 birds, including 83,000 raptors — eagles, hawks, falcons and owls — perished in wind turbines in 2013, according to a study published by Wildlife Society Bulletin.

"There's no doubt we're undercounting them and it's an outrage," Ramey said. "This is the dark side of green."

Jim Wiegland, vice president of the nonprofit Save the Eagles International agrees.

"The state of California, the federal government and the wind industry are obliterating wildlife and then publishing false and incomplete data to minimize the carnage," he said. "The wind industry gets a pass because it is supposedly reducing America's carbon footprint."

Some prominent American Indians, miffed that the government controls the market, have mixed feelings about the laws protecting eagles and other migratory birds.

"It cuts to the heart of who I am as a Comanche, that we need a piece of paper from the federal government to practice our religious beliefs," said William Voelker, director of the Comanche Nation Ethno-Ornithological Initiative. "But we need these laws to protect the birds who were slaughtered before they were passed and would face grave danger without them."

James Varney is a contributor at the American Media Institute.