(Updated 12:40 p.m. MDT, 1/02/23)
According to the West Yellowstone Police Department, after further investigation, it was determined that all of the bison were hit by the semi-truck. The two other vehicles were secondary incidents.
A number of bison were killed on Highway 191 Wednesday evening.
West Yellowstone Police Chief Mike Gavagan confirmed Thursday morning that 13 bison were killed around mile marker 4 on the highway. A viewer who asked not to be identified sent a picture of the scene to MTN.
The chief said one semi-truck and two other vehicles were involved. No one in the vehicles was injured.
Some of the bison had to be put down because they were so badly injured.
Gavagan said the accident happened around 6:30 p.m. on Wednesday. It was dark and bison are hard to see with their dark coats, and they do not have reflective eyes.
According to Gavagan, they are constantly trying to move bison off the road, and Wednesday night they were able to shoo ten to 14 bison off the road that were still there.
He also said it was not necessarily speeding but there was some concern of perhaps driving too fast for conditions. It's on a tough section of road that turns to head down the hill to the entrance to the transfer station.
Part of that road gets plowed and can be an easier crossing point for the bison.
The chief said sometimes they can get someone to harvest the bison, but you cannot get a salvage tag for bison because of brucellosis concerns. In the past, they have asked the Grizzly and Wolf Discovery Center, and they've taken some.
A Gallatin County sheriff's deputy, an officer from the West Yellowstone Police Department, an officer from Yellowstone National Park and the fire chief were all involved doing traffic control and helping get bison off the road after the incident last evening.