Laramie, Wy – Disagreement remains over what caused at
least 325 elk to fall critically ill south of Rawlins nearly a year ago.
While assistant state veterinarian Walt Cook blames usnic acid produced by lichen the elk ate, another state veterinarian, Merle Raisbeck, suspects some other toxin in the lichen.
The Game and Fish Department estimates that as many as 600 elk died last February and March. The elk became incapacitated, and those that did not die of thirst or predators had to be put down by wildlife agents.
It's the largest known elk die-off in Wyoming history.