Yellowstone bison: To shoot or not to shoot?

Mike Mease calls himself a "bison shepherd." And on the sagebrush-covered flats of Horse Butte, he and others from the Buffalo Field Campaign (BFC) are bracing for their biggest confrontation of the year.

Armed with video cameras and walky-talkies to coordinate strategy across hundreds of square miles, this ragtag group of environmentalists is on a mission: Usher Yellowstone bison out of harm's way when the rangy animals leave the national park and cross into Montana.

"We don't know how many bison will be slaughtered in the next few weeks, but all indications are that it could be a lot," says Mr. Mease in his stocking-cap beret. "We've already lost too many animals."

This winter, nearly 270 bison have been captured in Montana and sent to slaughter. Any day, hundreds more are expected to leave the park's snowy confines, searching for spring grass and a quiet place to birth their calves.

Waiting at Horse Butte is the Montana Department of Livestock, watching for the wild behemoths - the last major reservoir of buffalo known to carry brucellosis, a disease that causes nearby cows and buffalo to abort their fetuses.

Concern over possible transmission and its economic repercussions has only grown in recent months. Wyoming lost its "disease free" status for cattle when cows there were infected, allegedly after contact with contaminated wild elk. Nationwide, the livestock industry is still reeling from the nation's first verified case of "mad cow" disease in December. And in Montana, where there are more domestic cows than people, the loss of disease-free status could send the industry reeling.

Agricultural experts say the cost of an outbreak - quarantines, testing, and lost markets - would reach the tens of millions. "We have not had a case of brucellosis transmission here because agencies have been vigilant," says state Livestock Department spokeswoman Karen Cooper. "Part of that is lethal control."

For the Buffalo Field Campaign, the 2,700 Yellowstone bison killed here since the late 1980s are a rallying cry. Environmentalists suggest the threat is overblown, saying there's never been a documented case of brucellosis passed from bison to cattle in the wild. And Yellowstone's buffalo population is its own success story, with roughly 4,000 descended from a few dozen that survived a 19th century annihilation that erased tens of millions from the Great Plains.

Not all bison wandering into Montana are shot. Instead, Ms. Cooper says, "We're trying to be tolerant where we can." If park officials can't herd wandering bison back into the park, they steer them into pens for testing and, if results are positive, send them to slaughter. In the last three years, state and federal agencies have spent millions guiding buffalo back into the park - a tactic Mease calls a pricey attempt to stop migration.

Mease founded BFC seven years ago, after a winter when nearly 1,100 bison were killed. He found that marksmen typically wouldn't kill buffalo when he was present. When they did, he sent videotapes of the incidents to TV stations nationwide, outraging thousands. Ultimately, the state shifted to sending bison to slaughter.

"Slowly, we've been making progress," says Mease. Legislation drafted in Congress would impose a three-year moratorium on the killing. Residents' support for non-lethal management has grown; studies on a vaccine program are in the works; and ranchers are growing more tolerant of the diseased buffalo.

Initially, critics said BFC's vigilance would never last. But while tree sitters in old-growth forests of the Pacific Northwest have come and gone, BFC is anchoring one of the longest continuous environmental protests in U.S. history.

Over 1,700 people - from corporate executives to street people - have come from all states and several nations, says Mease. One is Anja Seddie, a librarian from Germany who heard of BFC's efforts on television. "Passion for buffalo is what inspired me to get involved," she says. "Discovering that I can make a difference is what brought me back a second time."

The BFC headquarters outside of West Yellowstone is run like a military camp - one in which many volunteers resemble young hippies at a Phish concert. Alcohol and drugs are forbidden. A log cabin is the nerve center, and tepees provide sleeping quarters for volunteers.

Rising daily at 4 a.m. and patrolling until sundown, the activists monitor both bison and agents' activities. They've "been bearing witness on behalf of bison every day" and had "a profound influence in changing the way government agencies treat these creatures," says Will Patric, coordinator of the Greater Yellowstone Wildlife Alliance. He acknowledges the controversy: Activists have been arrested for alleged civil disobedience, ignored police barriers in their filming, and erected roadblocks to prevent trucks from shipping bison to slaughterhouses. Cooper would not comment on such behavior, saying only: "As long as their actions are legal they have a right to be there." Others in law enforcement have called them "ecoterrorists."

Mease calls that slander, saying BFC condemns violence. "To see animals that you've come to know rounded up and slaughtered - it ... gets into your heart," he says. Among those in West Yellowstone, response is mixed. BFC offers a 24-hour service for residents to call for help in moving bison off their land and offers free labor to fix fences broken by bison. Volunteers along highways ask motorists to slow down when bison are present and have made signs for residents to post on their land telling the Livestock Department that animals are welcome.

"We're not here to create enemies," Mease says. "We're doing this to win friends for wild buffalo."

Such words resonate with Susan Dexter of Durham, Maine. rather than joining her daughter on a spring break, she headed to Horse Butte. "What [the workers] are doing," she says, "is a selfless act."