HELENA, Mont. (AP) — A judge has ruled against a conservation group's attempt to block the use of helicopters to haze wild bison into Yellowstone National Park.

U.S. District Judge Charles Lovell writes in his decision Tuesday the Alliance for the Wild Rockies had not shown the hazing significantly harms grizzly bears and their numbers are continuing to increase.

Last year, Lovell temporarily halted hazing after the group claimed the helicopters harmed the threatened species.

Helicopters are used to round up bison that left the park over the winter in search of food.

Alliance director Mike Garrity says the lawsuit forced state and federal agencies to consult with the U.S. Fish and Wildlife Service over grizzly impacts.

The Associated Press reports the group has filed notice that it intends to file another lawsuit.