The first days of a new bison hunt on the National Elk Refuge started slowly this weekend, with hunters harvesting two of the 300 animals officials hope will be taken by December.

Evanston resident Ryan Case shot the first bison, a bull, near the east border of the refuge just after 10 a.m. on Saturday. Case chased the animal on foot for more than a mile before killing it. Case’s wife and four young children accompanied him on the hunt.

Another hunter killed a cow bison on Saturday afternoon.

Case’s bull was the first bison shot on the refuge since the Fund for Animals successfully sued the U.S. Fish and Wildlife Service in 1998 to prohibit hunting there. The Fund for Animals argued that the refuge had not completed the necessary environmental process for a bison hunt.

The refuge completed the Jackson Bison and Elk Management Plan this spring and a federal court lifted an injunction on hunting there in August. The plan calls for culling 700 of the herd’s roughly 1,200 bison to help protect habitat and prevent disease on the roughly 25,000-acre property. Officials hope hunters will harvest 300 animals during this year’s hunt, which started Saturday and could last until December.

Refuge manager Steve Kallin said the hunt is a positive development in the refuge’s effort to manage the size of the bison herd. The bison herd is so large now that it’s causing serious damage to plant life on the refuge. Bison are also eating forage that’s intended for elk, he said.

National Elk Refuge officials say the bulk of the bison herd has not yet moved down out of Grand Teton National Park, making hunting opportunities scarce. Most of the 1,200 bison move onto the refuge at some point during the fall. Six or so licensed hunters took part in the first days of the hunt.

Conservation groups have raised concerns about the ethics of killing bison that come to the refuge to eat artificial feed intended for elk.

Groups like the Buffalo Field Campaign say the refuge’s supplemental feeding is to blame for a wide range of issues, including disease and habitat destruction.

Hunters are allowed to harvest bison on the part of the refuge that elk hunters have traditionally used in the past plus another 2,000 acres on the north end of the refuge. Officials also opened seven more miles of trails to vehicles, allowing hunters easier access to retrieve the animals.