Yellowstone visitor's attempt to help bison calf leads to its death

Yellowstone National Park staff killed a newborn bison after a visitor helped it cross a river, causing the calf's herd to reject it. Park rangers tried to reunite the calf with the herd, but the efforts failed, and the calf began approaching cars and people. The park staff killed the calf because it was abandoned by the herd and causing a hazardous situation. The park regulations require visitors to stay at least 25 yards from all wildlife, including bison, elk, and deer, and 100 yards from bears and wolves.