Yellowstone euthanizes bison calf after interference by park visitor.

Yellowstone National Park staff euthanized a bison calf after a visitor intervened in the animal’s struggle to cross a river Saturday. Park officials said in a news release the incident led to the animal’s death. According to the release, Yellowstone staff had to euthanize the calf after they failed to reunite the baby with its herd. Yellowstone National Park law enforcement officers are seeking information about an unidentified man who lifted the animal out of a river.