John Hollenhorst reporting In the last couple of weeks, government wranglers have captured more than a hundred buffalo near Yellowstone National Park.
They've also shot two and sent 63 to slaughter.
But, their efforts of control are not going unnoticed. There are spies, in them thar hills.
The people we call "Buffalo Spies" come from all over the world, trying to protect one of the icons of The West.
But some say their controversial methods interfere with an effort to control a costly disease.
The spies have been in the field every day for seven years. On stakeout duty in cars, looking for government agents. Stalking buffalo on foot. Always armed with a video camera.
Amy Zipperer, Buffalo Field Campaign : "YEAH, IT CAN BE HARD WHEN IT'S 50 BELOW IN THE MORNING AND YOU HAVE TO GO OUT. BUT IT'S WORTH IT."
The Buffalo Field Campaign drew its inspiration, and passion, from amateur videos like this.
In the mid-90's, federal and state sharpshooters took down buffalo, sometimes a herd at a time.
In all, about 2,000 were killed or sent to slaughter.
This one made a break for it.
Voice of amateur photographer: "The lone survivor." (bang!) "Guess not."
It's a campaign to prevent Brucellosis germs from getting out of the park.
Dr. Tom Linfield, Montana State Veterinarian: "We certainly feel that bison are a real risk as far as transmission to cattle."
The amateur videos caused an outcry. And the Buffalo Field Campaign has been shooting video ever since.
Ted Fellman, Buffalo Field Campaign: "Well we believe firmly that if people see what's happening here, they'll be outraged."
The volunteers live in an old lodge, and in tents, teepees and yurts. In their media center, videos are copied and sent out worldwide.
Over the years they've documented government workers capturing or "hazing" buffalo. That means shooing them back into Yellowstone with helicopters, cowboys, and ATV's.
The activists say there's no evidence bison can infect cattle. They believe it's all done to benefit ranchers.
Billy Williams/Buffalo Field Campaign: "To keep grass for cattle instead of buffalo."
Their passion occasionally leads to confrontation.
BFC Volunteer: "Do you deny chasing this baby's mother while it was birthing it?"
Relations with government are testy.
BFC Volunteer to Ranger: "Don't touch me!! I'm sorry. Don't ever! Ever!! Place your hand on me!"
Sometimes they deliberately interfere. In this case they erected and occupied a 35 foot high tripod, blocking a road until officers brought in a cherry picker.
Over the years there have been arrests.
Forest Ranger: "Are you refusing i.d.?"
Volunteer: "i don't have any id! I don't have any i.d."
"And then there is a more traditional method of getting media attention. A protest march down main street in Bozeman."
A huge banner hung from the tallest building drew a warning from police.
Bozeman policeman to protester: "The thing we can't have is people getting up on private buildings."
The march also drew snickers from passersby who believe Brucellosis is a threat to the cattle industry.
Aaron Fegles, Bozeman: "Well I think a lot of people in Montana, that's their livelihood. And for something to come in the way of it that's gonna start messing with their livelihood, you gotta be careful of that, especially in this state."
Volunteers claim public scrutiny has lowered the death toll. In recent years there's been far less shooting and capturing. Milder winters helped too, by encouraging buffalo to stay in the park. But this year the Buffalo population is booming, so the issue is back on Yellowstone's front burner.