See a herd of bison making a bridge bounce at Yellowstone

Bison on a bridge at Yellowstone
(Image credit: USA Today)

Ever wondered what happens when a herd of bison decides to cross a bridge? Here’s a very shaky video that reveals the answer.

The video was filmed by tourist Kevin Robert Madigan (and shared by USA Today), who was caught on a bridge crossing the Yellowstone River when a very large and lively herd of bison came thundering across in the opposite direction. As a result the bridge actually started bouncing, so much so that Madigan’s camerawork is bobbling up and down like the car’s been hit by an earthquake.

“They’re shaking the whole bridge,” you can hear someone cry from within the car.

“The whole bridge is jumping,” says someone else.

Madigan later described the experience on Facebook as “truly amazing”. 

There’s a much-repeated theory that if a platoon of soldiers is marching over a bridge, and the frequency of their footfall is closely matched to the bridge's frequency, then the soldiers’ rhythmic marching could actually shake the bridge to bits. These bison look like they could achieve the same without worrying about stampeding in formation. But luckily the bridge survived.

Not all encounters with bison end so happily. The US Park Service estimates that there are between 2,500 and 5,000 bison in the Yellowstone National Park region. 

The visitors in this video did the right thing by staying in their vehicles. The NPS advises that your car is often the best and safest place to view wildlife. It's not possible during a stampede, but ideally you should always stay at least 25 yards (23 meters) away from the animals. For more safety advice, see our guide how to avoid being gored by a bison.