A mass death of hundreds of elk in southern Wyoming last year had left the scientists baffled and pondering so long. The incident began in February 2004. Wyoming wildlife biologists and federal researchers have at last identified the chemical responsible for the cryptic death. According to them, usinc acid is responsible for it. It is a substance found in lichen, which the elk ate leading to the death of perhaps as many as 600 elk. Although all the bodies were not found, wildlife workers eventually found 327 dead elk on the prairie, Game and Fish biologist Greg Hiatt said. About 80 percent of them were cow elk.
A break came when a Wyoming biologist found an article from 1964 in which lichen was blamed for sickness and death in cattle and sheep. The elk herd in Jackson Hole area has a range of several hundred square miles and often crosses into Colorado above Craig and Steamboat Springs. Because of the drought that lingered into the winter of 2003-2004, biologists say they believe the elk moved out of their normal winter range into an area filled with the lichen, which grows on rocks and on the ground.