Just in time for National Park Week, a newly approved bill from the U.S. House of Representatives has reignited old debates over how America manages its national parks. Known as the "Sportsmen's Heritage Act," the bill would make several changes to the country's current park management style, and is already creating schisms within the hunting and conservation communities.

The bill is split into four main sections, but its most controversial parts deal with hunting in national parks and the types of ammunition hunters use. Among other things, it seeks to: open more federal land for hunting, exempt decisions on hunting and fishing from environmental review, allow polar bear trophies to be imported from Canada, and prevent the EPA from regulating ammo that contains lead, a toxic metal.

The House approved the bill 274-146, sending it next to the Senate, where it's expected to face a slightly cooler reception. Advocates see it as not just a policy issue, but as a defense of hunting itself. According to the Congressional Sportsmen's Foundation, the bill is "essential to recognizing the importance of, and facilitating the expansion and enhancement of, hunting and recreational fishing and shooting."

But conservation groups, including many that support hunting, call the bill a rollback of wildlife protections. "Instead of upholding values dear to many hunters, it degrades wildlife habitat on public lands and mandates continued use of known poisonous lead bullets and sinkers," Bill Snape of the Center for Biological Diversity says in a press release. "There are powerful reasons we banned toxic lead from gasoline, plumbing and paint; now it's time to finally rid this toxin from our bullets and fishing sinkers."

Some hunters and anglers prefer lead because it's cheaper, and dismiss scientific warnings about its toxicity. But aside from the potential health effects on sportsmen and women themselves, the lead also poses a risk to wildlife — and not just the ones being hunted. An array of studies have shown lead moving through the environment, often when bullet fragments or lost fishing sinkers are ingested by birds such as condors, turkey vultures, loons and bald eagles. One 2006 study found that lead bullet fragments in ground squirrels were poisoning hawks. According to the CBD, lead sickens and kills "more than 75 species of birds and nearly 50 mammals."

The EPA has mostly resisted pressure to ban lead bullets, arguing the Toxic Substances Control Act exempts firearms and ammo from the toxic substances it must control. Yet environmental groups cite an Internal Revenue Service ruling that the exemption "does not apply to sales of separate parts of ammunition such as cartridge cases, primers, bullets, and powder." A House report also found it "does not exclude from regulation ... chemical components of ammunition which could be hazardous because of their chemical properties." The new bill aims to end that debate, amending the TSCA to specifically exempt lead bullets and sinkers from EPA oversight.

Hunting and fishing is also already allowed in many parks and preserves run by the National Park Service, from Big Cypress in Florida to Mojave in California. And where it isn't allowed, there are often approved places nearby — you can't hunt elk in Rocky Mountain National Park, for instance, but you can hunt them in the Arapaho and Roosevelt national forests. And according to Craig Obey of the National Parks Conservation Association, some national landmarks are just not fit for hunting.

"There are plenty of public lands, both federal and state, that provide appropriate opportunities for hunting and recreational shooting," he says in a press release. "Yet in the absence of a perceived national need to hunt squirrels in Frederick Douglass's backyard, or conduct target practice at the Gettysburg Cemetery or the Flight 93 Memorial, the House has passed legislation that would seem to contemplate such ridiculous notions."

The bill does require that Bureau of Land Management and Forest Service lands be left open for fishing, hunting and shooting — "unless the managing agency acts to close lands to such activity for specified purposes, including resource conservation, public safety, energy production, water supply facilities, or national security." The CSF says keeping hunters and anglers out of national parks, monuments and preserves can lead them to abandon hunting and fishing altogether. "Access to areas to participate in these activities is one of the top reasons cited as to why sportsmen stop participating in their sports," the group argued in a recent letter to congressional leaders.

Another measure in the bill would legalize imports of Canadian polar bears that were shot before the species was protected under the U.S. Endangered Species Act. Federal law currently outlaws such imports, but the House legislation would grandfather in bear carcasses that were shot prior to the ESA listing.

And finally, a rider on the bill would limit the president's authority to designate national monuments under the Antiquities Act of 1906. That law, championed by President Theodore Roosevelt, has been famously used in the past to protect national landmarks such as the Grand Canyon and Olympic National Park. President Obama used it to designate Virginia's Fort Monroe a national monument last fall, and as recently as Friday he used it to create Fort Ord National Monument in California.

For more information about the Sportsmen's Heritage Act, formally known as H.R. 4089, see the bill's overview and history as well as the full bill text.

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Russell McLendon ( @russmclendon ) writes about humans and other wildlife.

U.S. House OKs 'Sportsmen's Heritage Act'
The controversial bill, which now heads to the Senate, would open more national parks to hunting and protect the use of toxic lead ammunition.