State and federal wildlife managers have begun a three-year study of elk wintering on the Fossil Butte National Monument near Kemmerer.

Officials involved in the project said about 25 cow elk were captured and fitted with radio collars last month to kick off the study.

The study is a cooperative project among the Wyoming Game and Fish Department, the U.S. Geological Survey, Northern Rocky Mountain Science Center, the Bureau of Land Management and the National Park Service.

The study will focus on the segment of the West Green River elk herd that spends part of the winter on the monument. The herd is well known to southwest Wyoming hunters, and the new information will allow Game and Fish to better estimate the herd's population, officials said.

Ed Olexa, wildlife biologist with the science center, said the study is necessary because the agencies share joint responsibility for management of elk in southwest Wyoming.

"Managers from Fossil Butte, the BLM and Game and Fish need to know more about how these elk use the land year-round," Olexa said in a statement.

"By collaring these elk, we should be able to delineate elk winter range on the monument, identify the spatial structure of the population that utilizes the monument, identify those areas that are critical to elk and most likely to be impacted by elk, and assist state efforts to obtain accurate animal population estimates," he said.

Olexa said initial study efforts will be focused on the monument, but additional elk may be captured on adjacent lands administered by other agencies.

Monument staff, Game and Fish biologists, wardens and their families began baiting elk with hay into the trap site in mid-December. Elk trapping began in mid-January.

Game and Fish Kemmerer biologist Ron Lockwood said the elk were captured in the coral and fitted with radio collars that are equipped with global positioning system devices or a neckband. The elk were ear-tagged, and blood samples were taken.

Lockwood said cow elk are being used in the study because biologists believe their movement patterns and habitat use are more representative of the herd than bulls.

The 8,000-acre Fossil Butte National Monument was established by an act of Congress in 1972. The popular visitors center located just west of Kemmerer in Lincoln County draws thousands of tourists each year from around the country.

The monument preserves a portion of the ancient Fossil Lake, which existed 50 million years ago in what is now the Green River Basin in southwest Wyoming.

Lockwood said the collar information will be tracked from the air and by crews on the ground.

"We used snowmobiles to pack down a trail to the top of a (nearby) ridge where the staff from Fossil Butte can monitor the elk from the ground," he said.