RAWLINS -- A small herd of elk is beginning to move south from the Red Rim area where 35 elk have died of apparent lichen poisoning since March 5.

"The good news is they're beginning to move south, but they're dropping along the way," Erin Smith of the Wyoming Game and Fish Department said.

The elk usually start migrating in late February to mid-March, depending on the weather. They move south to Atlantic Rim for the spring and then into the Sierra Madre Range and Colorado for the summer.

"We're mounting a full-force effort out there starting Monday morning with personnel from every district in the state," Smith said.

Game and Fish personnel have been using hay in an effort to get the elk out of an area where the lichen plant is more prevalent.

While some elk are responding to the hay, much more work is needed to scatter enough to be attractive to the elk.

Game wardens plan to lay as many bait lines of hay as they can Monday to entice about 300 elk currently using the Red Rim-Daley wildlife habitat area into places where there's less lichen, Smith said.

She said there is a lot of lichen and it is one of the few soft, green things available for elk in the area to eat.

Antelope eat it without any problems, but it's deadly to elk if they eat too much of it.

Smith said lichen samples are being taken to find out exactly what substance is causing the elk to become unable to stand or walk.

Researchers haven't yet found what in the lichen is toxic to elk.

The toxic chemical could affect the animals' muscles or the nerves that control muscles. Whatever the mechanism is, researchers say the result is the same: the elk go down, cannot get up or move their legs, but remain alert and responsive.