A ludicrously scenic byway isn’t even the main attraction at this US park

“Say hello to Bob everyone,” says Jim Palmer, our driver and guide. Bob is a 1000-kilogram male bison who’s clearly more interested in the lush grass in his creekside field than the five humans peering at him from an open-sided Jeep Wrangler.

It’s estimated that at the start of the 1800s there were about 60 million bison roaming the great plains of North America. But thanks to voracious hunting and a lucrative bounty put on them by the US government (a scheme designed to eradicate the main food source of Native Americans), that number plummeted to a few hundred by the 1890s.

Today, there are about 1400 of these majestic creatures in the 28,700-hectare Custer State Park in South Dakota, making it one of the largest publicly owned bison herds in the world. And while you’ve got a good chance of spotting them by self-driving around the park’s 29-kilometre Wildlife Loop, you’ve got an even better chance by joining one of the regular two-hour Buffalo Jeep Safaris.

First, let’s clear up a common misconception. Despite the name of the tour, bison aren’t buffalo. That moniker was given to them by Europeans who – somewhat bewilderingly – thought they resembled African Cape buffalo.

The other myth worth dispelling is that despite their bulky, cumbersome appearance – like a rhino draped in a shaggy bearskin rug – they are astonishingly nimble. A bison can spin faster than a horse, run at 55km/h and leap two metres high. Which means ol’ Bob there could jump clean over our Jeep.

Of course, the other benefit of joining a tour is the interpretation from the guide and Palmer is a human Wikipedia on bison. Who knew male bison roll in their own wee before mating? Or that bison don’t stampede like cattle? Or that females look “utterly bored” during sex?

Shortly after leaving Bob, we come across a large herd of mothers and calves, known as “cinnamons” because of their tan-coloured fur. There are no males in the herd; they live on their own for most of the year and only re-join for the rut, when they fight with other males for the right to seduce the herd’s largely indifferent females.

While bison are the headline act, the park’s sweeping plains and ponderosa pine-studded hills are also home to a wide supporting cast, including pronghorn (North America’s fastest land animal), whitetail deer, elk, coyotes, burros and a rich variety of birdlife. At one point we drive through a black-tailed prairie dog town and watch with amusement as two residents have an animated barked exchange from their respective burrows.