East to west is definitely the best way to see America, as it just keeps getting better. Each new State brings more drama, though this morning was all about the last bits of South Dakota. The best bits. The Black Hills of South Dakota are well known amongst bikers (the town of Sturgis holds the world's biggest biker festival every August). It's easy to see why. After miles of mainly flat scenery, these hills are full of great roads winding around some great sights.

The Harley isn't a sports bike but you'd be surprised how much it likes sweeping bends. The bike alone weighs around 400kg and my luggage must add another 30kg to that and I’m afraid I’m upwards of 100kg these days! It takes a lot to move it around but it's pretty good once it's going. I don't know how they do it but their roads are perfect. Wide, smooth, well-paved, grippy. Even the steepest mountains have perfectly easy roads up them. I don't think I've seen a pothole once.

I set off early having read that my first target, Mount Rushmore looks good in the early sun. It was only a 30 minute ride straight up into the hills. As you round one particular bend, you get your first view of the monument. And it is a bit surreal. Four huge faces carved on the side of a mountain. Only in America.

The visitor experience is as expected. This is a National Monument of enormous importance, and is treated as such. Easy car parking, a dramatic walk up to the rock along a walkway of state flags, a real sense of occasion about the place. And close up, it is pretty amazing. And the morning sun was doing a great job of showing them all in the best possible light. It felt like a cathedral here. I felt as though you needed to be quiet and respectful. There wasn’t much in the way of shops and cafes – which must have been a disappointment for your average American tourist. But here I was, one of only a handful of people early in the morning of Memorial Day at Mount Rushmore. I almost felt American!

I then took the short ride to the Crazy Horse monument. Here, almost within sight of Rushmore, the Native Americans are building their own stone carving. Of Crazy Horse riding his stallion and pointing - to show his lands I guess. This is being built without any government funding. It was started in 1947. They've done most of his head and are now working on his pointing hand and the horse's mane. At this rate, it could be a hundred years still to go. But it will be huge when completed. One-upmanship is alive and well round here.

The visitor centre is a great experience. There is little shouting about the ills of history, but there is a sense of injustice, a sense of now doing the right thing. Out here, this land really does feel like it belongs to them. Mount Rushmore may be something amazing but it's in the wrong place.

I descended through the northern Black Hills, passing old mining towns. One was called Lead which gives you an idea of what was mined here. The town of Deadwood was a proper old Wild West town but not kitschy like some I've been too. A very nice place.

And then I was back out on the plains again and crossing the border into Wyoming. I was headed for the Devil's Tower some miles to the north. This is a huge butte that just sticks out of the ground, made famous by the film Close Encounters. Somewhere I’d always wanted to visit, even if I couldn’t now get those 5 notes out of my head! The approach is once again dramatic and once you're there the sheer size is quite something. This place really matters to the natives and there is a sense of respect about it all. A great place for a rest and some lunch. I sat eating my sandwich watching the prairie dogs who are everywhere round here. Strange creatures, a bit like meerkats but with American-style love-handles.

I still had 300 miles to do in the afternoon to get to my destination of Cody. This would take me across a chunk of Wyoming. And what a place it is. Aside from Alaska, it is America's sparsest state. A population not much bigger than Bristol in an area twice the size of England. It has an epic sense of space and horizons that go on forever. Much of it is prairie but with a lot more interest. There are lakes, hills, vistas, valleys; it has it all. Still very green. This is cowboy country. Huge herds of cattle can be seen. Little fencing - what's the point out here. As I rode slowly over the hills around Gillette, I could suddenly see in the distance some real mountains. Proper big snow-capped ones. This was it. I'd reached the Rockies. I'd crossed the Great Plains and now I knew the landscape was really about to change.

I climbed the long steep road that led into the Bighorn mountains, a precursor to the Rockies. The views back of the plains were great. I crossed the snow line and carried on across this big range. There were thick snow-drifts on either side but the road was still perfect. Then I started to drop again and the views across the Bighorn basin were even more amazing. I didn't realise one could see that far from one viewpoint. I then crossed much of this Basin and ended up in the town of Cody.

And yes, Cody was the home of Buffalo Bill (and Annie Oakley). And it plays up to this. But it is a great little town. It's one of the closest towns to Yellowstone so is very touristy but it's a fun place and I managed to get a motel right in the centre so was able to wander out and find a nice bar and some more steak and some great company for the evening. I felt like a High Plains Drifter getting my well-deserved cold beer!