I looked at the enormous, overgrown snowmobile, canary yellow and in no way subtle. It was loud, stuffy, cramped and loud, even when it wasn't moving. I'm not getting in that Phileas Fogg contraption; that mad scientist school bus.

Cars are not allowed in Yellowstone National Park in winter, say you, sir? I like this place already. Can I sit up front?

So, I got to ride shotgun, and out here where there are bears, wolves, bison and coyotes, shotgun might be the appropriate word. The Snowcoach, as it's called, was incredible slow and meandering, like a downtrodden winter buffalo. Did I mention it was loud? Well it was, and the driver seemed able to hear everything I said even though I couldn't.

Yellowstone National Park, America's first, is packed in summer, when convoys of Winnebagos and campervans cross the country to belch crud into Wyoming's natural air. Ah, but in winter, you can only get in and out by Snowcoach, or snowmobile though they are trying to outlaw them, lord be praised. What that means, aside from the lack of humans in the park, is that local wildlife have the run of the place.

And this was abundantly clear when we came upon a herd of bison walking slowly along the road, which in winter, was their road.

"Pass 'em ," someone shouted from the back seat, someone who was eager to get to the Lodge for the next explosive instalment of Old Faithful.

"Can't," the driver whispered. Brilliant, I thought. The bison have right of way. Why can't the rest of the world be like this? The animals were here before us anyway.

Eventually, the bison got ahead because the driver stopped to check out a wolf kill he spotted by the Yellowstone River. Overnight snow had made all the tracks disappear but the carcass was enough to make me shiver. Under the bridge, a beaver was scampering around cleaning house and banging wood.

Back on the road, the bison had turned off and we had free use, for the time being. The Snowcoach made my teeth rattle but I had the biggest smile on my face.