How far will the National Rifle Association go to overthrow gun control measures? Apparently infiltrating groups who favor gun control isn't out of the question. Among the groups infiltrated? Apparently the National Parks Conservation Association.

Mother Jones magazine, in a story published Wednesday, reports that a woman known as Mary McFate has over the years worked undercover as an NRA mole who infiltrated gun control groups. Among the more recent targets was NPCA, which has been working for months against efforts by Interior Department officials to overturn gun regulations pertaining to weapons in the National Park System.

Under the current guidelines, weapons owned by licensed gun owners can be brought into the parks, but they have to be broken down and stored out of easy reach. Earlier this year, however, Interior Secretary Dirk Kempthorne proposed to replace that regulation with one that would allow park visitors to arm themselves around the clock if the laws of the state in which the park in question is found allowed.

What's not been answered is how rangers in park units that span multiple states -- such as Yellowstone, Death Valley, the Blue Ridge Parkway, and Great Smoky Mountains -- would police gun laws if this proposal were embraced.

A source for the Mother Jones story, Barbara Hohlt, executive director of States United to Prevent Gun Violence, told the magazine that Ms. McFate's ears perked up when she heard about NPCA's opposition to the change.

McFate also took a keen interest in a gun matter currently under consideration by the Department of the Interior, Hohlt says. At the urging of the gun lobby, the agency has been mulling whether to change its regulations to allow people to carry loaded and concealed guns into national parks under certain circumstances. (At the moment, a gun carried into a national park must be unloaded and kept apart from ammunition.) The National Parks Conservation Association and current and former National Park Service officials have been fighting the proposed rule change. "When Mary heard about this," Hohlt recalls, "she immediately asked to be on the email list [of the opponents] and she also got on the phone calls. So she now knows the strategy of the people trying to fight this."

NPCA officials, understandably, are aghast at the possibility that their private deliberations have been overheard by a spy possibly working for the NRA. In a statement issued this afternoon the park advocacy group confirmed that Ms. McFate "has participated in multiple confidential conversations and email correspondence over the past few months about efforts to keep visitors and wildlife safe in our national parks."

Bryan Faehner, NPCA's legislation representative, adds that, "If the investigation by Mother Jones proves true, then the NRA will have effectively spied on our ongoing efforts to keep visitors and wildlife safe in our national parks. If true, this is a troubling display of the lengths to which the NRA will go to further its agenda."