Two black bears and a bison calf have died in recent weeks in Yellowstone National Park because of humans/NPS file

Visitors to Yellowstone National Park are taking a toll on the park's wildlife. In recent days two black bears have been killed by motorists, an elk and a bison were also hit by vehicles, a newborn elk calf was picked up by motorists concerned for its fate, and a bison calf had to be put down after a visitor tried to help it out of the Lamar River so it could catch up with its mother.

"In recent days, some actions by visitors have led to the endangerment of people and wildlife and resulted in the death of wildlife. The park calls on visitors to protect wildlife by understanding how their actions can negatively impact wildlife," a park release Thursday evening said. "Approaching wild animals can drastically affect their well-being and, in some cases, their survival. When an animal is near a campsite, trail, boardwalk, parking lot, on a road, or in a developed area, leave it alone and give it space."

The highest profile incident happened on May 22 when a visitor from Hawaii thought he needed to help a bison calf keep up with the herd after it crossed the Lamar River on the park's northern range.

As the calf struggled, the man pushed the calf up from the river and onto the roadway. Visitors later observed the calf walk up to and follow cars and people. Park rangers tried repeatedly to reunite the calf with the herd, but their efforts were unsuccessful. The calf was later euthanized by park staff because it was abandoned by the herd and causing a hazardous situation by approaching cars and people along the roadway.

On Wednesday the visitor, Clifford Walters, pleaded guilty to one count of feeding, touching, teasing, frightening, or intentionally disturbing wildlife. He was fined $500, and ordered to make an additional $500 Community Service payment to Yellowstone Forever Wildlife Protection Fund, and saddled with an additional $30 special assessment and a $10 processing fee.  

On May 28 at about 5 p.m., an adult male black bear was struck and killed by a vehicle near milepost 14 on U.S. Highway 191 in the northwestern section of the park, according to the park release. Later that same evening a second adult male black bear was struck and killed by a vehicle at milepost 29 on U.S. Highway 191. Both bears were dark chocolate brown in color.

Additionally, in recent days one elk and one bison were hit by separate vehicles, the park reported.

Finally, during the Memorial Day weekend visitors placed an elk calf in their car while likely driving on U.S. Highway 191 in the park and brought the newborn to the West Yellowstone, Montana, Police Department. The elk later ran off into the forest and its condition is unknown. The incident was under investigation and there was no additional information to share.    

Last year there were two known incidents of visitors getting too close to bison, resulting in the animals responding to the perceived threat by goring the individuals.

Park regulations require that you stay at least 25 yards (23 meters) away from all wildlife (including bison, elk and deer) and at least 100 yards (91 meters) away from bears and wolves. Disregarding these regulations can result in fines, injury, and even death.

Park staff ask that you protect Yellowstone National Park by taking the Yellowstone Pledge, act responsibly and safely, and set a good example for others. If you see someone, in person or online, whose behavior might hurt them, others, or the park, tell a ranger. If you’re in the park, dial 911.