Yellowstone Park

You will be savaged should you ever visit Yellowstone Park. There's a multitude of wildlife to choose from but, even if they leave you alone, nature does her own savaging.
Assaulted from every side by rivers, mountains, waterfalls, cliffs, rockfaces and an array of geologic phenomena operating on a time scale we can appreciate. Plus, frozen lakes. If you visit in summer, I suspect, it could be hell on earth.
There is also a very real sense of having been transported back in time. The custodians of the park have obviously shunned modern technologies such as television and the internet. And it's a bloody good job too.
They've also kept most of the park building free. The exceptions - Mammoth Hot Springs, Norris, Madison, Old Faitful, Canyon Village, Lake Village, West Thumb and Grant Village - are very tastefully arranged, particularly Old Faithful and Lake. Old Faithful is all wooden cabins and the Inn is just gorgeous. Lake, on te other hand, is yellow and pink. Despite this it, also, is a place to die for. You will feel as if you have been transported into an Agatha Christie whodunnit. The scenery is simply impossible to describe. If beauty is in the eye of the beholder, I'd like to meet the beholder that first sees the lake and the Absarokas and considers it anything other than utmost beauty.
The giveaway is that from about 20 miles out, everybody is grinning from ear to ear. They do this because they are in a part of the world that, hourly, presents new aspects of candy to the eye. You don't want to be there when it goes off, although you don't want to be anywhere on this planet when it goes off, so yu may as well enjoy it while you can. As for cycling, by all means, but expect hills.
And when you leave, it doesn't stop at the Park's limits. North you have the Yellowstone River Valley (the Yellowstone is apparently the U.S.' longest undammed river), East, the Shoshone River Valley, South, the Tetons and West the mountains of the Continental Divide and the Rockies.
Go and enjoy.