In the grand scheme of wildlife management, 25 Yellowstone National Park bison are not that big of a deal, not when the park's herds are pushing 4,000 animals.

But if 25 are allowed to freely roam into Montana and onto national forest lands to the north of Mammoth Hot Springs, they could begin laying the foundation for much greater tolerance of bison in Montana.

In the coming week or so that plan will be put into motion, as bison, possibly "encouraged" by wranglers, make their way onto the Royal Teton Ranch and continue north via a fenced corridor onto the Gallatin National Forest. The experiment -- which cost $2.8 million alone to obtain the ranch's grazing rights -- has been years in coming, and while conservationists would like to see more bison allowed to head north, they agree it's progress.

"When you look at the big picture of expanding habitat for bison and increasing tolerance for bison outside of park boundaries, it is a step forward and progress," Patricia Dowd, the Yellowstone program manager for the National Parks Conservation Association, said Wednesday. “Is the approach the best way? I’m not sure, in terms of hazing and moving the bison that way (to the north). Is it ideal? No, but I guess the long-term hope is that once bison are taught to move north and they’re allowed and tolerated then they’ll just naturally do that.”

Montana livestock officials long have worried about Yellowstone bison ranging freely into their state. Some bison carry a disease called brucellosis, which can cause cows (and elk and bison) to spontaneously abort their fetuses. While there never has been a documented case of bison transmitting this disease to livestock, Montana officials don't want to take any chances; losing their state's "brucellosis free" status would be costly to ranchers who would have to test all their cattle for the disease.

This intolerance for Yellowstone bison has led over the past decade and more to both hazing of bison back into the park and outright hunts that have killed thousands of bison. Already this winter some three dozen park bison that wandered outside of Yellowstone have been killed by state-authorized and tribal hunters, according to Yellowstone spokesman Al Nash. Park officials also have looked into the potential of a vaccination program to inoculate bison against the disease.

With hopes of finding some middle ground, back in 2000 a team of biologists and officials from Yellowstone, Montana, as well as U.S. Forest Service personnel and tribes got together and developed an Interagency Bison Management Plan aimed at both permitting a wild bison population and protecting Montana's brucellosis-free status.

Now, almost three years ago this interagency committee worked out a deal under which up to 25 bison a year -- and possibly more down the road -- could roam north of Yellowstone through property owned by the Church Universal and Triumphant to reach traditional wintering grounds on the Gallatin National Forest. While not a significant number, in light of the more than 1,700 bison that were killed outside the park during the winter of 2007-2008 in the name of brucellosis prevention, conservationists at the time applauded the agreement as a first step.

Now officials are ready to move forward with that plan.

This past Tuesday a group of 23 bison was hazed into a fenced pasture at the park's Stephens Creek capture facility northwest of Gardiner, Montana, just inside the Yellowstone boundary. Once enough bison are corralled, biologists will test the animals for exposure to brucellosis. A group of 25 bison will be selected from those that test seronegative for brucellosis exposure. Those animals then will be marked and fitted with monitoring devices, and released and moved to the Gallatin Forest where they will be allowed to remain until spring.

“We’re probably going to have a couple of riders move them north (from the Stephens Creek facility)," Mr. Nash said Wednesday. "The target area is a few miles north of the park. We want to get them up there so they can be out there and not get confused with any other (bison) that may venture across the park boundary.”

Montana crews, meanwhile, have built a fenced-in corridor to lead the bison through private lands and onto the national forest, he said.

According to a release from Yellowstone, once the various state, federal and local agencies "have determined they have gained significant experience with this small group, in subsequent years they will allow first up to 50 and ultimately as many as 100 untested bison on the same landscape. The agencies may adjust these numbers based on this intermediate phase of the management plan."

At the Natural Resources Defense Council field office in Bozeman, Montana, wildlife advocate Matt Skoglund shared Ms. Dowd's tempered enthusiasm over the plan.

"Any increased tolerance for bison outside the park is a good thing. But clearly, this is not enough," Mr. Skoglund said. “Just the 25 and then they allow for more in the future. Any tolerance outside the park is a good thing, but clearly this isn’t even close to enough. There is a lot of suitable habitat for wild bison outside the park.”

In a related matter, Montana Fish, Wildlife and Parks Commission officials are expected to be asked late next week to approve a plan under which brucellosis-free Yellowstone bison would be relocated elsewhere in Montana.

Bison for such a relocation would come from a quarantine project that Montana officials and the U.S. Agriculture Department's Animal and Plant Health Inspection Service have been running just north of Yellowstone near Corwin Springs, Montana.

"The first group of those bison to move through that program were placed on one of Ted Turner’s ranches," Mr. Nash said. "There are a couple of more groups of bison that will soon be ready to be moved out of the quarantine somewhere.”

The quarantine project was designed to take calves from Yellowstone and see if it was feasible over time to develop a genetically diverse herd of animals that tested seronegative for brucellosis, the park spokesman said. Those animals then would be freed elsewhere in Montana in areas thought to be free of brucellosis, he said.

This would enhance the genetic pool of bison in and outside of Yellowstone and allow for additional bison herds "in appropriate places" in Montana, said Mr. Nash.