Bison are being trapped once again in Yellowstone National Park.

A total of 193 bison were trapped Friday and probably will be shipped to slaughter, park spokesman Al Nash said Friday.

When the work is done, more than 900 Yellowstone bison will have been killed this winter, and the season is far from over.

"Unfortunately, I don't think this is the end," said Mike Mease, a co-founder of the Buffalo Field Campaign, a bison activist group.

He said he expects to see 400 to 500 bison leave the park's west boundary, and more could exit on the north side.

The animals captured Friday had strayed about five miles north of the park boundary and were near the Corwin Springs Bridge on the west side of the Yellowstone River.

Rangers herded 170 of them back inside the park, to a series of pens erected to hold them. Later in the day, 23 more bison that had been in a horse pasture on the east side of the river hopped the fence and swam the river to the west side.

Rangers then rounded them up as well, Nash said.

Meanwhile, the Montana Department of Fish, Wildlife and Parks announced it is closing the bison hunt in the Gardiner area five days early so that bison can be hazed away from livestock.

The hunt was scheduled to close Feb. 15, and the early halt could be a largely moot point.

Of the 50 tags issued, 40 have been filled. The remaining 10 tags were granted to Indian tribes, some of which weren't interested in participating.

It's possible that one more person from one of the tribes will want to hunt, according to Pat Flowers, regional director for FWP. If that happens, the hunting zone around West Yellowstone can be reopened, he said.

The bison rounded up Friday were on land belonging to the Church Universal and Triumphant. There are cattle on parts of that land.

There are still bison on the east side of the river, in a "no-tolerance" area where cattle and horses were grazing. Agents from FWP and the Montana Department of Livestock planned to haze those animals closer to the park Friday, Flowers said.

Mease said 12 more bison entered the "no-tolerance" area late Friday, so there might be more hazing over the weekend.

The National Park Service plans to ship all 193 animals to slaughter as soon as transportation and slaughter facilities can be arranged, Nash said.

The Park Service has already shipped 583 bison to slaughter and another 87 to a brucellosis quarantine test facility.

Add in the 40 killed by hunters and it means a total of 903 Yellowstone bison have been removed from the park's herds this winter, plus a handful that were shot or died in the park's bison trap at Stephens Creek.

The herd numbered 4,900 animals at the start of winter.

Nash said rangers had been hazing the bison daily for two weeks, but they kept leaving the park.

Bison don't get much leniency in Montana because the beef industry fears they will spread brucellosis to cattle, though that has never happened in wild conditions.