BOZEMAN, Mont. (AP) - Hunters have killed 39 bison to date in Montana's first bison hunt in 15 years, and some lawmakers already are talking about expanding the hunt for next season.

Mel Frost, a spokeswoman for the state Department of Fish, Wildlife and Parks, said 39 bison were killed as of Saturday in the hunt that began Nov. 15 and is set to end Feb. 15. The number included six bison killed under licenses issued to American Indian tribes in Montana, she said.

An additional five bison were killed over the weekend by members of the Nez Perce Indian tribe of Idaho, she said. Those animals were killed under an 1855 treaty between the United States and the tribe, and the hunters were not subject to the rules of the state-run hunt of bison that leave Yellowstone National Park.

Frost said only one of the general public tags has yet to be filled, but she expects the hunter who has the tag will kill a bison before the season ends.

"I think the hunt itself has been a great success," said Sen. Gary Perry, R-Manhattan, the lawmaker who sponsored the 2003 bill that authorized the hunt.

Perry said the hunt is a useful too, but not the only solution, to dealing with bison that leave Yellowstone each winter.

Montana ranchers fear the bison, many of which carry brucellosis, could spread it to cattle herds.

Perry said now that the state has proven the hunt can work, he would like to see it grow.

Mike Volesky, a natural resources adviser to Gov. Brian Schweitzer, also called the hunt a success. Once things are analyzed, he said, officials will figure out how many tags to issue for next winter's hunt, which he said will include "more tags and maybe a longer season, but definitely more land area, too."

Bison advocates have criticized the hunt, partly because livestock regulators have a big say in it and partly because they say it doesn't include enough territory for a "fair-chase" hunt.

"It resembled a fair-chase hunt more than it did in the past," Volesky said. "By and large, hunters conducted themselves respectfully. Folks opposed to the hunt did the same."