A herd of bison almost trampled tourists in Yellowstone

The national park is home to about 6,000 bison, and when they migrate, they take to the roads.

A video posted to Instagram shows the massive animals approaching a parked snowmobile at full speed, only to swerve to the side of the road at the last second.

The bison population in Yellowstone has fluctuated in recent years between 3,000 and nearly 6,000. In winter, the animals migrate up to 100 km from their summer ranges to areas with less snow.

Since the first US national park is open to visitors year-round, it is not unusual for these migrating bison to walk onto roads or snowmobile trails in front of vehicles. Park rangers also warn that it is possible to hit a bison while riding a snowmobile. And it will likely end badly for the snowmobile.

Rangers also note that bison have mauled more people in Yellowstone than any other animal. They are unpredictable and can run three times faster than humans — not to mention that bison can weigh up to a ton and have sharp, 14-inch horns on their heads.

Yellowstone rangers advise keeping your distance from bison, but if you do encounter them, they recommend walking calmly the other way, or even running if the bison starts snorting and pawing the ground.

"As always, remember that while visiting and supporting national parks is great, you are an intruder in these animals' homes. Respect their space and don't be an idiot," the experts advise in closing.