Yellowstone National Park is a reservoir of brucellosis. The livestock disease got there a century ago when infected cattle roamed freely inside the park, and now, brucellosis has been all but eradicated in domestic livestock, says Yellowstone Spokesman Al Nash.

Bison in the park can carry the disease, which is why the livestock operators surrounding the park are nervous about an Interagency Bison Management Plan that seeks to allow bison to migrate north of the park while also preventing transmission of the disease.

The typical way bison are kept in the park is by riders on horseback hazing them, but that works only so many times.

Limited patience being herded:

"If you haze bison several times, they get very difficult to haze and they can become rather obstinate, and that can pose a threat to the riders and their horses. And then they go to the point where we do capture those animals."

Mr. Nash said there are now two places that captured bison can be held, Stephens Creek and now the Brogan Bison Facility, which is north of the park boundary.

Holding facility outside the park:

"The most recent change in our approach to bison management is in our ability to use another bison facility, which is located outside the park boundary for us to use to hold bison for spring green-up as part of the other thrust of the IBMP, which is to conserve our wild bison population."

There are about 600 bison currently being held, with the Brogan Facility holding only bison that have tested negative for brucellosis, about 60 bison. The Stephens Creek facility is near capacity.

Last month Montana Gov. Brian Schweitzer imposed a 90-day ban on shipping bison through his state to slaughter, which was how they managed overcrowding in the past.

Slaughter option rescinded:

"We've never had any transmission of brucellosis from bison to cattle, under any circumstance, including during transport to slaughter."

An Associated Press Report said Wednesday that state and federal agencies, and others, have been meeting for about a month with eventual goal of allowing bison to cross in and out of the park's northern boundary. An announcement from the closed-door negotiations is expected next week.